WebM: What you need to know about the Google media format!

A new file format for multimedia appeared on the Internet in 2010, assisted by Google. WebM is an open-source alternative to other video formats (especially to MP4) and is specifically intended for Internet use in combination with HTML5. What can this WebM format do that other video formats can’t?

What is the WebM format?

WebM is a container format (with the file ending *.webm) for multimedia files, i.e. for videos and audio files. Within this container, the video codecs VP8 and VP9 and the audio codecs Vorbis and Opus are used. First announced at the Google conference I/O 2010, WebM was planned as an alternative to the existing MP4 format with its H.264 codec from the beginning. Although the latter can be used at no cost to the consumer when viewing videos, developers who wish to work with the codec need to pay license fees. WebM, on the other hand, is an open-source project that can be used by everyone without charge.


WebP is a sister format developed especially for viewing image files online.

WebM is designed for use with HTML5. The codecs VP8 and VP9 have been designed in such a way that there is a lot of compression, but that little computer power is required when unzipping the files. The aim of this design is to make online video streaming possible on almost any device (such as a desktop, tablet, smartphone or media device such as a smart TV). It is therefore not surprising that YouTube – part of Google – converts all videos to the WebM format, irrespective of the format of the original file. Nevertheless YouTube continues to support H.264 for those who are unable to use WebM.

WebM has since become a political issue within the online community. While Google is making every effort to establish the audio/video format, other major market participants such as Apple or Microsoft continue to use formats such as MP4. The main reason for this are the patent laws: both of these software companies are part of the MPEG-LA patent pool, as they hold patents for the codecs used and receive license fees for them. Google is attempting to get around these patents by using WebM.

In the past, this has led to various legal problems in Germany, for example. The issue was with the VP8 codec. Several companies complained that the codec was violating their patents. Google subsequently came to an agreement with MPEG LA. However, Nokia is not part of the patent pool and is of the opinion that its rights have been violated. An initial case, in which the company sued its competitor HTC, whose devices support V8, was dismissed by Mannheim district court in the south of Germany.


Codec is a combination of the two terms “code” and “decode”. Two algorithms ensure that the video data are first encoded in order to keep the file size small and then decoded in order to restore the images and sound correctly.

WebM files can be integrated into a user’s own website simply by using the HTML5 video tag.

<video width= "320" height="240" controls>
    <source src="video.webm" type="video/webm">

WebM player: How do you use a WebM file player?

WebM is already supported by some of the major web browsers: no further installations are required by Chrome, Chromium, Firefox and Opera to play files with this format. Microsoft Edge requires an additional plug-in. Apple Safari can also be upgraded to play the WebM format – at least as far as its desktop version is concerned. iPhone and iPad users do experience problems: they need to install additional software to play the video format on their devices.

The most popular software for playing WebM files is probably VLC player. This is also available for devices with the iOS operating system. Winamp and Kodi are also able to play WebM files. Windows Media Player 12 is also able to handle WebM. However, the WebM Media Foundation components need to be installed. This also makes it possible to play videos in WebM format using Internet Explorer.


In the meantime, solutions have also been developed for compiling WebM videos: thus, for example, there are plug-ins for the popular video-editing tool Adobe Premiere, which you can use to export your videos directly in WebM format. A number of converters that can be used to convert existing videos in other formats into WebM can also be found online.

WebM vs MP4 – advantages and disadvantages

While WebM is a relatively recent development, MP4 (MPEG-4 Part 14) and H.264 have been in use for many years. This means that the older format and the codec have become a standard: you will find few applications that do not support MP4. In addition to online services and PC/Mac software, many other devices (e.g. video cameras) can handle MP4. This high degree of acceptance means that the format is of interest to both manufacturers and users.

However, Google does well with the open-source nature of WebM: using the format does not result in any costs for either the manufacturers, developers or end users. The software is also being marketed under the open BSD license.

The licensing network behind MP4 or H.264 is obscure: most users – including those compiling professional videos – have no idea whether they have a valid license after purchasing hardware or software or whether they are violating licensing laws each time they compile or watch a video. With WebM things are much clearer. MPEG LA did announce in 2010 already that the use of H.264 codecs will remain free of charge in future, provided that the videos compiled are made available to users free of charge.


Both WebM and MP4 are only containers. In order to assess both quality and performance, the codecs used need to be evaluated. For WebM these are VP8 and VP9. MP4 mainly operates with H.264 and more rarely with its successor, H.265.

For many users, the performance of the two formats is more important that the patent arguments: In recent years, H.264 has rightly reached the top position among the codecs. The quality of MP4 videos with this coding is generally regarded as very good. However, H.265 still easily outperforms them. WebM has an equally convincing image and sound quality, but VP8 does not fall entirely into the same class as H.264. The extent to which VP9 matches H.265 (also called HEVC) with regard to image quality is a hot topic. Some are of the opinion that they are equals, others say that the quality of VP9 is nowhere near that of H.264.

Two other decisive features when comparing the codecs are file size and the speed of coding and decoding. Both have a direct effect on usability: to ensure rapid online data transfer, the file size should be as small as possible. This is particularly important for mobile internet users. However, H.264 is known to generate comparatively large files. However, on the user side, decoding takes place very quickly and is not particularly complex. This once again is linked to the common use of the codec. Many devices already support the decoding of H.264 videos from a hardware point of view.

This is not the case for H.265 – which may have something to do with the very high licensing costs payable by hardware manufacturers. The more recent codec requires a lot of computer power, which may particularly lead to problems with smartphones. WebM is specifically intended for streaming applications and yields good results, both with regard to the file size and the speed. Once again the lack of prevalence is a problem here: although many Android devices have installed support for VP8 and TV manufacturers such as LG, Samsung and Sharp are gradually equipping their devices with VP8/VP9 support, iPhones, iPads and other Apple devices still do not provide any hardware support. This means that their performance can be expected to be much poorer.

  WebM MP4
Codecs VP8, VP9, Vorbis, Opus H.264, H.265, AAC, MP3
Quality Good quality Better quality
File size Small files Large files
Prevalence Mainly supported by Google Very common
Patents Open source Licensable
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