How to pay without creating a PayPal account

Credit Cards
Image by Sean MacEntee

Many services all over the world wide web require you to pay via PayPal. Why? Because it’s easy, convenient, and provides many useful features, securities, and possibilities for both, buyers and sellers. Yet, not everyone feels safe using and registering for PayPal, and linking their bank account information to their new PayPal account. PayPal fraud is still something many people are afraid of. All that’s needed – most of the time – is clicking on one link to give your private information to someone on the other side of the net.

Some sellers, however, offer you to pay for their services via PayPal without creating an account! If you, for example, want to sign up for one of the premium services of, all you need is a credit card.

If you decided for the service package you want to purchase, you will be automatically directed to PayPal. The standard view is the one displayed below. Yet, after being prompted to log in to an existing PayPal account, many don’t look further. If you want to pay with your credit card without signing up on the page, you should do that though. Click on “Pay with Debit or Credit Card”.



Now, you are presented with a form that requires the information about your credit or debit card. Depending on your country, you may also be asked to enter your address, email address, or phone number. To continue after entering all the information necessary, simply click on “Pay now” at the bottom of the form.



Afterwards, you will be asked whether you want to create a PayPal account. If you decide to do so, you can register with the information entered. If you still have no desire to use PayPal more regularly by entering your information, you can – of course – decline.

With getting the confirmation of PayPal that your purchase has been made, the services you ordered will be available for you immediately.


Problems you may encounter

While offers the service of paying with credit card instead of creating a PayPal account, not everyone does. Sellers can choose to disable this feature, only enabling you to pay when having an account with PayPal.
Furthermore, it may be that your country isn’t supporting this kind of payment. In case the problem lies within PayPal though, it may help to clear your browsing data and delete the cookies.

If PayPal is not accepting your credit card, it may also be that you already have an account that is linked to your card’s information, preventing the site to pay with it without logging in.

For more information about paying with credit or debit cards, please visit the PayPal customer support page or refer to this announcement.


EDIT 11/08/2016: We have updated the screenshots and our article since PayPal did a few changes.

Convert Text to Audio

Image by Marina Montoya

There are so many possibilities to convert across different file types – aka cross conversion – but what is it all good for? We looked at several types of cross conversions already, showing why you may need them, how useful they are, and how easy the results can be obtained.

After extracting text from pictures, ripping audio from a movie clip, and other useful conversions, we will look at the so-called TTS today; Text to Speech.

What’s TTS good for?

There are several reasons for you to convert text to audio, actually. Plus, such conversions bear advantages for different groups of people like elders, students, business men, or dyslexics.

Listen to lecture notes, text books, etc.

Instead of printing out endless lecture notes and spending hours reading through text books, one can add more value to studying very easily. By turning text and documents to audio, another kind of learning input is given. Next to reading your material, you will be able to listen to it as well.

Plus, you can go through important notes anytime from anywhere by transferring the resulting MP3 file to your iPhone, computer, or other mobile device.


Proofreading is important for many texts, may it be applications, assignments, take-home exams, or even a thesis. By writing, one can find many spelling or grammar mistakes, yet what about the content? Finding holes and discrepancies can be a lot easier if you hear your own work read out to you.

Speech preparation

Have an important presentation or speech coming up? Then listen to what you are about to say. Inconsistencies, and halting expressions can be detected a lot faster. Plus, you’ll get a rough overview of how long your speech or presentation will take.

Avoiding eyestrain

Reading tiny fonts; may it be in documents, emails, or on websites – can be very straining for the eyes. As is reading when you are dealing with stress or headaches. If you still need to know about the content of an email or text asap, letting it read out to you is a good solution.

Audio books

The TTS conversion is also an easy way to get an eBook or PDF turned into an audio book. Listen to it yourself or create some kind of radio play for your children that way.

Help those with reading problems

Especially people with reading problems can benefit from text turned into MP3 or another audio format. This is especially true for dyslexics, language learners, or blind and visually impaired people. Elders that do not want to read through long emails or children that aren’t too versatile in reading yet, gain from a text read out loud as well.

How to convert text to audio

Creating an MP3 or WMA file from your texts and documents is fairly easy. You can convert many different document files like DOC, ODT, TXT, or PDF into any audio file format available as a target. For demonstration purposes, we chose an MP3 converter.

MP3 ConverterAfter choosing the fitting converter for your needs, all you have to do is browse your computer or hard drive for he document you want to convert. The source file we wanted to be converted to speech was a DOCX document with lecture notes.


After clicking on convert file, the only thing you have to do is wait. Depending on how big your text file is, the upload, conversion, and download may take a little longer. In the end though, you’ll have your text converted into an audio file that’s ready to be listened to.

Audio File


Average File Sizes

Image by daveynin

There is one thing about files that everyone can’t help to notice as soon as they want to download, upload, or send it via the internet, or when the computer announces that there isn’t enough storage left: File sizes.

No matter if you store music on your iPhone, want to send a picture via email, or upload a funny video to Facebook, file sizes – when too big – can and will cause problems, especially when you are on mobile or stuck with a slow internet connection.

There are natural limitations, no matter if they are set by your email provider for attachments, or by different pages when you want to upload a video or profile picture. Keeping the kilobytes and megabytes in mind prevents you from encountering unnecessary problems.

Why’s File Size important?

As stated above, there are a number of reasons why you would want to keep the size of your files in mind. One we encounter almost daily is the limitation set by many email providers when it comes to attachments. Consider this for example:

An attachment for an email sent via gmail can not exceed 25 MB, while emails sent via Microsoft Outlook allow for individual files (not the whole bundle) to not be bigger than 20 MB.

This may not seem to be a problem at first when you want to send a picture or PDF document, but as soon as you want to send multiple files or even a video, matters become more pressing. Thankfully, most email programs let you know when you exceed the file size limit.

Another factor are upload and download times. Sure, for many users, the download of a file takes about 15 seconds, but households that still have a dial-up or other slow connection can take up to one hour for a file with a size of 10 MB. Thus, when uploading documents or other media to share on the internet, you should also keep in mind people that aren’t blessed with highspeed internet connections.

Same goes for uploading an entire album of photos to Facebook, for example, or a video to YouTube. While users of a fast internet connection can easily wait through the uploading process and even browse the net meanwhile, some people still have no chance of doing anything on the internet while the upload is in process. Especially people with a slow connection who want to upload their videos, music, or images would have to keep a close eye on the file size of their media.

Especially nowadays, mobile internet is the number one way for people to connect with the world. Yet, even if many mobile phone providers have internet flat rates in their contracts, the download speed is limited in most cases. Thus, browsing pictures or watching videos can be very annoying considering the long loading or buffering times when you are stuck with mobile internet.

Bits and Bytes

Which units are there even, and how big are they? Refer to this short list:

  • 1 B = 1 byte
  • 1 kB = 1.000 bytes
  • 1 MB = 1.000 kB or 1.000.000 bytes
  • 1 GB = 1.000 MB, 1.000.000 kB, or bytes

Average File Sizes

But, what are the average file sizes of media we use daily? After browsing the net and producing some examples ourselves, we found out the following:


  • PNG ~ 2 – 4 kB
  • GIF ~ 6 – 8 kB
  • JPG ~ 9 – 12 kB
  • TIFF ~ 900 – 1.000 kB
  • BMP ~ 900 – 1.000 kB


  • DOCX ~4 – 8 kB
  • PDF ~ 18 – 20 kB
  • ODT ~ 80 – 90 kB

Media Files

  • eBook ~ 1 – 5 MB
  • MP3 song ~ 3 – 4 MB
  • DVD Movie ~ 4 GB
  • HD Movie ~ 5 – 8 GB
  • Blu-Ray Movie ~ 20 – 25 GB

Reducing File Sizes

Reducing the size of individual files can be achieved in different ways.

Image files can easily be cropped using different photo editing software or online editors. Photographs for displaying on the web or in Facebook do not have to be big in dimension. Buttons, lines, clipart, and the like can even be stored as formats that are smaller in size because they don’t contain much color or style information, like PNG or GIF. However, uploading RAW camera images (like CR2 or NEF) are 2 to 6 times bigger than JPG files and can’t be displayed correctly anyway. TIFF and BMP files should be converted to JPG or the like as well since they are bigger in size than the compressed JPG files.

Document files that should be displayed online or provided as a download can be slimmed down as well by getting rid of unnecessary pictures and formatting. In most cases though, saving as or converting your file to PDF correlates with a reduced file size as well.

Video files can be treated similar to image files, yet getting and mastering a video editing program is much harder and takes longer than achieving the same with photo editing software. However, changing the screen size by using a video converter is be a fast and easy to use alternative.

Last but not least, bigger audio files can be converted to MP3. This goes hand in hand with loss of quality to some degree, yet for your listening pleasure this should be marginal.

Different Hash Functions and their Advantages

Hashing Functions
Image by Isaiah van Hunen

In former blog entries we have talked about what encryption, encoding, and hashing are and what you possibly might need checksums and hashes for. The names of several algorithms and ciphers that can be used for creating hashes or processing encryption have been mentioned as well, yet, which system should be used for which purpose?

This is the purpose of this article. Let’s have a look at different kinds of hashing and encryption ciphers you can use to produce checksums. This list is, by far, not exhaustive and only lists ciphers supported by the free online hash encryption tool available on this site.


CRC stands for cyclic redundancy check. It’s purpose is to check chunks of raw data for error and (accidental) changes. CRC’s popularity comes form it’s ability to be implemented and analyzed easily. Furthermore, the system is exceptionally good in detecting common errors.

CRC-32 is especially popular as an built-in check.


In 1995, Mark Adler invented the checksum algorithm Adler-32, which is a faster modification of the earlier Fletcher algorithms. Adler-32 checksums are created by calculating two 16-bit checksums. Afterwards, they are linked to form one 32-bit integer. Regarding reliability, one could place Adler-32 between Fletcher-16 and Fletcher-32, whereas the speed is higher in both cases. IN general, Adler-32 is a very fast algorithm, faster than the CRC equivalent as well.

The disadvantages of Adler-32 lay, as initially stated, in it’s reliability. Furthermore, checksums created this way can be forged easily and thus do not suffice to protect data against modification. The support for short messages is also one of Adler-32’s weaknesses.


Blowfish is used widely among cipher suits and encryption products for it provides a good encryption rate. The symmetric-key block cipher has been designed in 1993 as an alternative to DES. Its big break through was due to the fact that it was free to use for the public domain though, something quite unique at that time

The weaknesses of Blowfish lie within it’s liability to attacks depending on the key used. Also, files with a bigger size than 4 GB shouldn’t be encrypted using Blowfish. Nowadays, it’s successors Twofish and Threefish are gaining more and more attention.


Contrary to the 32-bit hash function Adler-32, GOST is a cryptographic hash function that supports 256-bit. It’S based on the Soviet and Russian standard GOST block cipher. It was the Soviet alternative to DES which was used in the US, both ciphers showing strong similarities in structure.


SHA-1 and it’s “brothers” was designed by the NSA. They are cryptographic hash functions with different support of bit rate. SHA-1 produces 160-bit hash values, SHA-256 256-bit, SHA-384 384-bit, and SHA-512 produces 512-bit hash values. SHA stands for “Secure Hash Algorithm”, and especially SHA-1 is widely used in a number of applications.

While SHA algorithms are not used to secure data, they have gained big success in ensuring that data remains unchanged. It is said that nobody has been able to “break” SHA-1 yet even though it is merely a consistency check.


HAVA, much like the ciphers mentioned above, is a cryptographic hash function. It can produce hashes in different lengths, varying from 128 to 256 bits. Furthermore, users of HAVAL can specify the number of rounds that are used to generate the hash.

Yet, several weaknesses of the cipher have been found in HAVAL variants which makes the usage quite questionable nowadays.


Tiger is also a cryptographic hash function, designed to run on 64-bit platforms. Different versions of Tiger (Tiger-128, Tiger-160, and Tiger-192) allow for different hash sizes. Distinctive initialization values are not defined with Tiger. The fixed amount of rounds used to create a hash with a Tiger function is 24.


Also a cryptographic hash function, SNEFRU was invented in 1990 and supports 128 and 256-bit values. Despite earlier weaknesses to attacks, the function has been developed further, resulting in quite some resistance against attacks.


Whirlpool is a cryptographic hash function as well. Developed in 2000, it was recommended for usage by the NESSIE (New European Schemes for Signatures, Integrity and Encryption) project. Whirlpool can easily be implemented, existing versions containing a version written in C and in Java. Like Blowfish, Whirlpool is also available in the public domain. One of the best known programs to use the Whirlpool algorithm is TrueCrypt.

Document Files Microsoft Windows Programs can open

Microsoft Word
Image by Quinn Dombrowski

In a former blog post we have looked at all kinds of media files that can be opened by programs that come with Microsoft Windows like the Movie Player or Photo Viewer. Today, our focus is on document and spreadsheet files that are native to the Microsoft Office Suit or can at least be opened by these Windows programs.

So, even when you are using another Open Source Office Suit, people using Microsoft Word or Excel may be able to open the native files you send them.

For this, we will focus on the newest Microsoft Office Suit programs as well as WordPad and NotePad.


Microsoft Word is, by far, the most well known word processing software there is today. The first files listed are all native to Microsoft Word 2013 or earlier versions:

  • WPS (from Microsoft Works)

The following files can be opened in Word as well:

  • PDF
  • RTF
  • TXT
  • XML, XPS

This last file listed is native to other text programs but that can be opened in Word nevertheless. Yet, formatting and styles are often differently stored across the files, thus it may happen that the formatting looks different when opening such files in Word.

  • ODT


Replacing Microsoft Write, WordPad is a less versatile word processing software that comes with the Windows installation package. Editing and applying basic formatting to texts is possible with this program as well.

  • RTF
  • TXT
  • DOCX (earlier versions could also open DOC)
  • ODT


The most basic text editing program that is meant to edit, save, and make use of basic text without formatting is Microsoft’s NotePad. It’s especially neat and functional when creating webpages since the resulting files can be stored using various codes like Unicode or UTF-8.

  • TXT


Excel is a spreadsheet processing program that allows you not only to create tables and graphs, but also to conduct basic and even advanced calculations. Again, first listed are the native files that can be produced by using Microsoft Excel 2013 and earlier versions:

  • XLW

The following (spreadsheet) files can be opened by Excel as well:

  • CSV
  • PDF
  • TXT

This open source produced file type can be opened in Excel as well, yet the formatting may look different:

  • ODS


Native file formats produced by this presentation software include:


Also, the following files, even including image and video files, can be opened in PowerPoint:

  • MP4, WMV
  • PDF
  • RTF
  • XML, XPS

The open source file used for storing presentations that can be opened by PowerPoint is:

  • ODP

Unfortunately, while the support of files produced by most open source programs is given, neither Word, Excel, and PowerPoint, nor WordPad or Notepad support opening native Mac files – at least not without having to install various plugins. In this case, it is advised to convert the files in question (e.g. KEY or PAGES) into a supported document format.

Best free Image Editing Programs

Photo Editing
Original image by Tambako The Jaguar

If you work on a computer and like taking pictures (and even if not) you have heard about programs like Photoshop for sure. But that means you also know how expensive they are to get. Since we have presented you with a list of the best free office programs already, we thought it’s about time to present you the best free or even online accessible programs for photo editing.

First, we will concentrate on three open source image editing software that you can download and install for free. Yet, some features may require payment. Then, we will also present three online options on how to apply filters on your images or add text and clipart. Those may contain paid features as well though.

Open Source Software


GIMPGIMP is most probably the number one go-to tool for people that do not want to purchase Photoshop. It was developed for computers running with Windows, Mac OS, and Linux. Most features that are available in Photoshop are available in Gimp as well, even though the interface looks different and may appear quite familiar to someone who’s used to the Photoshop interface.

The most common features like adding layers, textures, overlays, and different filters are a part of the service of Gimp. Of course it is possible top open several pictures to edit them in one session. There are plenty tutorials on how to achieve certain effects, and program is still updated regularly.

Pictures can be saved as (or exported as) many different formats including the “usual” picture files like JPG, PNG, GIF, BMP, and Tiff, as well as more exotic formats and even PDF. The editable project filr of GIMP is saved with the XCF extension.


Paint.NETPaint.NET is a program developed for windows desktop computers. It features most features PhotoShop has as well, like adding and removing layers to the picture, applying gradients or other drawings and text to the image, and limitless undoing of changes made. Filters like noise, distortion, or blur can be applied as well.

Several pictures can be opened and worked on at the same time while the user interface is intuitive and shows strong resemblance to Photoshop as well. Tutorials on how to achieve a certain effect in Paint.NET exist as well. Despite the website looking rather outdated, the product is still updated regularly.

Next to the option of saving the edited images in the popular formats JPG, GIF, PNG, TIFF, and BMP, the option to save the picture as TGA and DDS files exists as well as the option to store the picture with all it’s layers intact as a Paint.NET project file with the PDN extension.


KritaKrita is a picture editing program that focuses mainly on editing digitally made paintings and illustrations. Yet, the program offers nearly the same features as the two formerly mentioned programs, thus making editing photographs and other images just as easy.

Next to creating different layers and the usual tools like adding filters, cropping, color fill, and gradients, Krita offers different symmetry tools and drawing aids as well. Thus, it’s advantage definitely lies in the support for artists that want to perfect their digital or scanned drawings.

The project file for Krita has the extension KRA, yet edited pictures can be saved as JPG, PNG, BMP, and TIFF, and even as the Photoshop picture format PSD.

Online Photo Editing

If you need a faster solution and do not want to download software and install it on your computer, these online picture editing programs may be the right thing for you. All you need is the picture you want to edit and a working internet connection.



At first glance, the advertisement on the right side when launching the web application of Pixlr may seem annoying, but you can easily escape this by using this service in fullscreen mode.

The features presented by Pixlr don’t leave many wishes unfulfilled. Under “Adjustment” you can find the basic adjustments like contrast, red eye treatment, and rotating, but also a tool to liquify parts of the picture or doodle on top of it. Under “Effect” you can find a big variety of filters to apply to the image, grouped into categories, providing the option to favorite certain filters and a preview of how it will look applied to the image. Further features are overlays like bokeh, borders, stickers, and text.

One of the best things about the editing in Pixlr is that you can add one effect to the picture and then choose whether you really want to apply this effect to your picture permanently. Of course there’s an undo button as well.

The fully edited picture is saved in the JPG format.


BeFunkyContrary to Pixlr, the BeFunky photo editor doesn’t allow a fullscreen mode to escape the advertisement, yet there are other features that make up for it.

Having a closer look at the “Essentials”, it’s apparent that BeFunky aims more towards retouching or portraits and creating pictures for your social media profile. For example, there’s the option to remove wrinkles, add make up, and even crop the image to fit the Facebook cover size. There’s a big set of filters to apply to the image as well with an extra navigation point for “drawing”-style filters, yet some of them require upgrading. Other features include adding a border, stickers, text, or a pattern or texture to the picture. When applying a texture, the option to change the blend mode (just as in Photoshop) is given as well.

Again, you can apply the effect and look at the edited picture before deciding whether you really want to apply the effect.

When saving the picture, next to choosing to save the edited image on your computer, you can directly upload it to Facebook, Tumblr, Flickr, or another site as well. When saving, you have the option to choose between JPG and PNG, and choosing the quality of the picture will even give you information about the file size.


PicMonkeyThe last one of our list is PicMonkey, an online tool that displays advertisement very subtly at the bottom of the page.

Next to the basic edits, the tool also provides basic filter options to apply to the image. Yet, many of them are so-called “Royal” features that require upgrading and thus payment. Similar to the BeFunky photo editor, the service offers tools to retouch portraits. The basic retouching options are for free, yet most of them “Royal” features. More features include adding text, stickers, borders, and textures that even allow you to upload your own textures and apply them to the image. In case you can’t decide which overlays and effects to use, there’s also the option to choose a theme like Winter or Comic Heroes and make edits that are suggested.

When saving the picture, you are able to choose between the JPG and PNG format. An option to change the dimensions of the image is given as well. Of course you can also share your edited picture on Facebook, Twitter, or another page.

Media Files supported by Windows Software

Image by Les Haines

There are many free programs you can use to watch videos, listen to audio files, or view pictures and images with. Yet, not many people feel comfortable downloading and installing unknown software – especially since some can’t even open all formats. After having had a look at native Apple files before, we will have a look at media files that are supported by Windows native programs this time.

We will concentrate on Media files like videos, audio files, and images only this time (with the exception of some project files), since document, presentation, and spreadsheet files is a topic for another day.

If you still come across an audio or video file that isn’t supported by your Windows native programs, you can still convert them into a format that can be displayed or played by them. You don’t need any download or installation for these audio converter or video converter as well.

Windows Media Player

The most current version of the Windows Media Player, Media Player 12, got rid of quite a few restrictions the Media Player 11 version still held. It is part of the Windows 7 Starter Edition, Home Premium, Professional, Ultimate, and Enterprise.


The support of MP4 and M2TS files as well as 3G2, 3GP, and 3GPP files doesn’t come as a big surprise. Especially MP4 became a very popular format for videos and movies, thus the implementation and support by the Windows Media Player was just a matter of time.

What’s more noteworthy is that Windows Media Playe 12 also supports Apple resp. Mac formats as well now, such as MOV and M4V.

  • 3G2, 3GP, 3GPP (not available in Media Player 11)
  • AVI
  • M2TS (not available in Media Player 11)
  • M4V (not available in Media Player 11)
  • MOV (not available in Media Player 11)
  • MP2
  • MP4  (not available in Media Player 11)
  • MPG
  • WMV


While the Apple native formats AIF and AIFF have been supported by Windows Media Player before, the Media Player 12 version added support of the M4A file format as well. Furthermore, AAC files can be listened to with the Media Player as well now.

  • AAC (not available in Media Player 11)
  • M4A (not available in Media Player 11)
  • MP3
  • WAV
  • WMA


Windows Movie Maker

For getting the most current version of the Windows Movie Maker, Windows Movie Maker 12, the Windows Essentials 2012 package is necessary.


The following project files that contain information about the video, audio, and other editing processes can be opened and further edited in Windows Movie Maker 12:

  • WLMP


  • WMV
  • M2TS, MTS
  • AVI
  • MP4, MOV, 3GP, 3G2
  • MPEG, MPG, MP2


  • WMA
  • M4A
  • MP3


  • GIF
  • BMP
  • ICO
  • PNG


Windows Media Center

The Windows Media center allows you to watch TV Series, movies, DVD content, and more on your computer. It’s available in the newest version for For Windows 8, 7, RT, and Vista.


  • WMV
  • M2TS
  • MOV
  • AVI
  • MP4, M4V
  • MPEG, MPG, MP2


  • WMA
  • WAV
  • MP3
  • AAC


  • RAW
  • GIF
  • BMP
  • PNG


Windows Photo Viewer

The Windows Photo Viewer is the default program to view images, photos, and pictures of several formats since Windows 8, 7, and Vista.

The most popular image formats are supported by the Photo Viewer, but it unfortunately does not cover camera raw formats like ARW, CRW, or NEF.

Furthermore, animated GIFs are displayed as still images rather than animated. To display an animated gif in motion, one either needs Internet Explorer (or any other browser) or another picture viewing program that supports animated GIFs.

  • PNG
  • GIF (no animated GIFs)
  • BMP

Create animated Gifs from Movies

Animated GifEveryone loves animated GIFs!

They are smaller in size than movies and focus on the short sequences you want to re-watch or share. They are view-able without a problem in all browsers on almost every device. Reactions to forum posts, funny sequences from videos, pointing something out in a specific scene – those are just a few reasons for why you may want to create a moving and animated GIF.

Most people use Adobe Photoshop or another photo-editing software to create these small moving pictures, but not everyone knows how to utilize them – or can afford buying such a program. Using a GIF converter, however, is a quick and easy way to get your favorite scene as an animated GIF – and it doesn’t cost a thing!

How to make Animated GIFs

The Video

At first, you need the movie or video you want to convert, of course. It doesn’t matter which format the movie is in – MOV, AVI, MP4, MKV, etc. – what counts is that it isn’t too long.

When uploading a longer video, only the first 30 seconds will be converted into an animated GIF. Thus, if you want a specific scene to be “giffed”, it would be better to cut the video into short portions of no longer than 30 seconds. This can either be done with a video editing software, or by using the option of cropping a video e.g. on this free MP4 converter.

Once you have the cut or short video – or several short videos – you can start with the “real” GIF making process!

GIF Image Converter
Select the GIF image converter

Get that GIF

After you have the video(s) you want to convert, visit the GIF Image Converter page. There you can browse for your video and select it. Basically, you are good to go now. Click on “Convert File” and wait. Your animated GIF will download after the conversion is finished.

Animated GIF Conversion
Standard Settings. Just press “Convert file”

Yet, there are a few ways in which you can edit the GIF by choosing different options before the conversion.

  • Change Size: Change the size of your resulting GIF, e.g. 400 px width (height will be adjusted in proportion)
  • Color: Change the color of the GIF to greyscale, monochrome, negate, or another color scheme.
  • Enhance: Add different filters to your GIF, like sharpening, despeckle, and more
Edit Animated GIFs
Example settings for editing your GIF

Here you have a few examples on how the GIFs can turn out:

Animated Gif
No additional settings
Animated GIF
Settings: Gray + Sharpen
Animated GIF
Settings: Year 1980 + Equalize
Animated GIF
Settings: Year 1900 + despeckle

Checksum & Hash – What are they and what do I need them for?

Image by Isaiah van Hunen

In an earlier article, we have talked about the difference between encoding, encryption and hashing already. Today, we want to have a closer look at the latter of the three, the hashing function and the resulting hash or checksum.

For this purpose, we will have a brief look at what a checksum is before we concentrate on what checksums are used for.

What’s Hashing?

Using a hashing function creates a hash or checksum which are basically a seemingly random string of numbers, letters, and special characters – depending on the algorithm used for the hashing.

For example, the result of hashing “Testing Hashing Functions” with the Blowfish function would result in the following hash:


This hash is unique to the sentence used to create it (using the very same system). Thus, you will be able to determine whether a set of data has been altered by creating another hash, for example of “Testing Hashing Function” without the plural ‘s’. The hash differs from the one above:


While hashes are thus a way to secure your data when, for example, sending it over the internet, the function is not reversible. This means that the input used to create the checksum or hash can not or very very hardly be generated using the checksum, even if the function used is known.

Examples for Hashing functions include: Gost, SHA-3, Tiger-160, Whirlpool, and other hash generators.

What is Hashing used for?

Hashes and checksums can be used for several purposes, some of which are listed below.

Searching in a big database

Creating hashes of database entries helps the user, administrator, or program to find certain entries in the database a lot faster than a real character-by-character search. Names, titles, headlines, or anything else ‘search worthy’ are assigned an individual hash or checksum. Entering a keyword into the search will generate a hash for said keyword as well, quickly comparing it to the hashes inside the database, and delivering the matching result.

Checking downloads

Some sites that provide the download of programs, example files, or anything else, also provide the correlating checksum to the download. This is important at times, since you surely don’t want to download a corrupted file or one with a virus. Thus you can compare the hash or checksum generated from the file you downloaded, and compare it to the one given to you by the website you got it from. If the checksum differs, the file is not the same one that has been used to generate the checksum you got for comparison.

Checking transmitted data

Another use of checksums and hashes is that they can be used to compare data that has been written to a disk or external hard drive with the original one to rule out transmission errors. Sometimes, the transmission of data to another device is interrupted or incomplete for other reasons. Instead of checking the data individually, one can simply compare the ckecksums made of both, the original data and the one on the device.

Password comparison

As the owner or administrator of a forum, online shop, or another website that uses a password function, it’s wiser to not store the user’s password in your database. The database is (more or less easily) hackable, and thus the password information of the users would be accessible to every hacker that is interested in it. Saving the hash value or checksum of the passwords s a lot saver since the original password can not be derived from it. Yet, comparison of the hash value stored and the hash created when the user enters his password will still determine whether the same password has been entered.

Duplicate content

Looking for duplicate content, either across the web or in a large file, it can become a very time consuming task. Here, hash value comparison simplifies and quickens the task as well. Services that provide looking for duplicate content across the web or plagiarism software rely on using checksums or hashes for the most part.

How to Open Unknown Files

Unknown Files
Image by Dennis Hill

Did it ever happen to you that you downloaded a song or video clip, or someone sent you a file via email and once you want to open and view it, it doesn’t work? Of course you wonder why, and after checking the file you see that you may have never heard of this kind of file before. Don’t panic. The next time you encounter such an unknown file, you will be well prepared!

In this article, we will tell you how to easily handle unknown file formats, and what you can do to use them on your computer without installing any additional software.

What’s the File Extension?

The first thing to do when you find a file that you can’t open is to find out what file extension it has. Because once you have the extension’s name, you can find out what kind of file it is and how you can open it.

Find the file in question and click on it with your right mouse button. Depending on what OS you use (Windows or Apple) a list of options will pop up. One of them should be “Properties” or something similar (also depending on the language of your computer). Once you clicked on it, a pop up window will open which lists all the properties of your file. When using Windows, you will have a point that says “File Type:”. There you will find the necessary information about your file type, e.g. PDF-File (.pdf)

The file extension are the letters following the dot in the brackets. In this case, the file extension would be PDF.

What kind of File is it?

Now that you know what kind of file extension you’re dealing with, it’s time to find out what kind of file it is. A document, an image, or maybe a music file? Or something else entirely?

The easiest and most informative way to do so is by referring to a list of file formats where you can easily search for the one in question. Such lists not only give you information about the developers and all kinds of technical data about the file type, but also about the programs with which you can open them!

For example, you found an AIF file on your computer. Searching the list linked above, you find a listing under “Audio Files.” Now you know that this file was developed by Apple, contains audio data, and can be opened by the Quicktime or Windows Media Player.

How to open/view this File?

In the best case, you can now choose the program you prefer to open the file, may it be a document file or a spreadsheet. But what if you don’t have any program from the list presented installed on your computer? Instead of having to install yet another video player or Office suit program, you can easily convert your file into a format that the most popular programs can open.

Unfortunately, especially when it comes to video files, there can still be problems when you want to play a video that contains codecs that are not installed on your computer. T find more about these cases, you can read our article about video codecs and containers.