OneTaskBy Tim King · Updated
Codec Support Checker
Which Video Formats Your Browser Plays
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How the Codec Support Checker works
This codec support checker tests the browser you are using right now and shows which video formats it can play, stream, decode, encode and record. It covers H.264, HEVC, AV1, VP9, VP8 and common audio codecs. The results appear as soon as the page loads, and you can save them as a text report.
A video file is a container, such as MP4 or WebM, holding streams compressed with a codec, such as H.264 or AV1. A browser can only play the file if it understands both. Support varies by browser, operating system and even graphics hardware, so a clip that plays on one laptop can show a black box on another.
What the codec support checker tests
| Column | Browser feature | What a Yes means |
|---|---|---|
| Plays | canPlayType on a video element |
A plain video tag can play this format |
| Streams (MSE) | MediaSource.isTypeSupported |
Adaptive players such as HLS.js can use it |
| Decodes | VideoDecoder.isConfigSupported |
WebCodecs can decode 1080p frames of it |
| Encodes | VideoEncoder.isConfigSupported |
WebCodecs can encode 1080p at 5 Mbit/s |
| Can record | MediaRecorder.isTypeSupported |
Browser recorders can save this type |
canPlayType answers "probably", "maybe" or nothing. The table shows these as Yes, Maybe and No.
"Maybe" usually means the container is known but no codec was named, so the answer depends on the
file.
Typical results
| Codec | Chrome and Edge | Firefox | Safari |
|---|---|---|---|
| H.264 | Yes | Yes | Yes |
| HEVC | With hardware support | Windows with hardware support | Yes |
| AV1 | Yes | Yes | Newer Apple chips |
| VP9 | Yes | Yes | Mostly yes |
These are broad patterns, not guarantees. Run the check on the device that matters.
Tips and pitfalls
H.264 is the safe choice. For a video that must play everywhere, use H.264 video with AAC audio in an MP4 file.
Hardware matters for HEVC and AV1. Many browsers only play them when the graphics chip can decode them, so two machines with the same browser can differ.
MOV and MKV are containers only. A Maybe for these means the browser might open the file if the codecs inside are supported. Many MOV files from iPhones hold HEVC.
Recording types decide what browser tools can save. Chrome records WebM and, in newer versions, MP4. Safari records MP4.
How to read the result
The stats count how many formats play and how many recording types work. Save the report to compare devices, or to attach to a bug report about a video that will not play.
FAQ
Why will a video not play in my browser?
Usually the codec inside the file is not supported, even if the container is. An MP4 holding HEVC plays in Safari but may show a black frame in other browsers. Check the table for the codec, then convert the file to H.264 if needed.
Does this test upload anything?
No. Every check is a question the page asks your own browser, such as canPlayType. No video is loaded and nothing is sent to a server, so the result reflects only this browser on this device.
Why do Plays and Decodes give different answers?
They use different parts of the browser. The video element may use the operating system's decoders, while WebCodecs may expose a smaller or larger set. Players built on either will follow its own column.
What is WebCodecs?
WebCodecs is a browser interface that gives web pages direct access to video and audio encoders and decoders. Editors and converters use it for fast frame-accurate work. If it shows Not available, those tools fall back to slower methods.
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