Free WebM sample files
A royalty-free video format for the web: VP8, VP9 or AV1 video in a restricted Matroska container. Download valid WebM test files in 4 exact sizes, from 100 KB to 5 MB, each with a checksum.
- Extension
- .webm
- MIME type
- video/webm
- Kind
- Binary
- Category
- Video
WebM files by size
Every file below is a valid WebM video file of exactly the stated size. Open a file's page for its checksum and contents, and to preview it in your browser before downloading.
| File | Size | Contents | Download |
|---|---|---|---|
| 100 KB WebM samplesample-webm-100kb.webm | 100 KB102,400 bytes | 640 × 360 px | Download WebM |
| 500 KB WebM samplesample-webm-500kb.webm | 500 KB512,000 bytes | 640 × 360 px | Download WebM |
| 1 MB WebM samplesample-webm-1mb.webm | 1 MB1,048,576 bytes | 640 × 360 px | Download WebM |
| 5 MB WebM samplesample-webm-5mb.webm | 5 MB5,242,880 bytes | 640 × 360 px | Download WebM |
What is a WebM file?
WebM is a subset of Matroska that Google introduced in 2010 for HTML video. It limits the container to a few open codecs: VP8, VP9 and, more recently, AV1 for the picture, with Vorbis or Opus for sound. Any Matroska tool can read a WebM file.
It is the format browsers produce themselves. The MediaRecorder API, which records a camera, a screen or a canvas, writes WebM in Chrome and Firefox.
How to recognise a WebM file
Software recognises a WebM file by its file signature: fixed bytes at the start of the file, also called magic bytes or a magic number.
| Extension | .webm |
|---|---|
| MIME type | video/webm |
| Container | Matroska subset with the document type "webm" |
| Video codecs | VP8, VP9 and AV1 |
| Audio codecs | Vorbis and Opus |
| Browser support | Chrome, Firefox, Edge and current Safari |
What to test for
These are the behaviours that most often go wrong when software handles WebM files.
- Recordings made in the browser usually lack a duration and an index, because both are only known when recording stops. Players show no length and cannot seek until the file is remuxed.
- WebM and MKV share a signature, so a sniffer has to read the document type to tell them apart.
- H.264 and AAC are not allowed in WebM. A file with those codecs and a .webm extension is really Matroska, and browsers may refuse it.
Strengths of WebM
- Royalty-free codecs, and playable in every current browser.
- The format browsers record natively through the MediaRecorder API.
Limitations of WebM
- Hardware decoding for VP9 and AV1 is missing on older devices, which costs battery.
- Poorly supported by editing software and by older Apple devices.
Typical uses of WebM test files
- Testing HTML video with a second source beside MP4
- Checking uploads of browser-recorded video
- Verifying type detection between WebM and MKV
- Testing transcoding from WebM to MP4
Software that opens WebM
- Chrome, Firefox and Edge
- Safari 14.1 and later on macOS
- VLC and mpv
- FFmpeg and libvpx
- The MediaRecorder API in browsers
Specifications
Related
WebM sample files: questions
- Which codec do the WebM samples use?
- VP9 video at 640 × 360 and 30 frames per second, with no audio track.
- Can the WebM samples be seeked?
- Yes. They declare their duration and carry an index of key frames ahead of the picture data, unlike a raw browser recording.
- What is the MIME type of a WebM file?
- The MIME type is video/webm. The file extension is .webm.
- Is a sample WebM file the same as a dummy or example WebM file?
- Yes. Sample, test, dummy and example WebM files are different names for the same thing: a WebM file with known contents that stands in for a real one. Any file on this page will do wherever a tutorial or a test plan asks for a dummy WebM file.