How to check your browser's supported video formats
See which video codecs your browser reports as supported, learn why a file may still fail to play, and what to check next.
A video plays in one browser but not another, or the page shows a blank picture, an error, or no sound. The file extension alone may not explain the problem because video files can use different encoding formats inside the same type of container.
Use the Browser Info tool to check which codecs your browser reports as supported. Then compare that information with the video and narrow down whether the issue is browser support, the file, or playback conditions.
Check the browser's video support
- Open Browser Info in the browser where the video fails.
- Find the codecs section and review the video and audio codecs listed there. Make a note of the browser and version shown too.
- Check the video's actual format details in the player or source information, if available. Look for the video codec and audio codec, not just the file ending such as
.mp4. - Compare the codecs in the file with the codecs the browser reports. If the video works in a different browser, check Browser Info there as well, using the same device and file.
- Try playing the same video in the original website or app again. Note whether the picture, sound, or both are missing, and whether you see an error message.
A codec is the method used to encode or decode the picture or sound. Common video codecs include H.264, VP9, AV1, and HEVC. Common audio codecs include AAC and Opus. A playable video needs support for both its video and audio tracks.
What the result means
The browser reports support for the video's codecs
The browser reports that it can handle those codecs, so the extension or codec is less likely to be the only problem. Support does not guarantee that every file using that codec will play. A particular profile, level, resolution, bit depth, damaged file, or website restriction can still cause trouble.
The browser does not report support for a codec
The browser may not be able to decode that track. This can happen even when the file ends in a familiar extension such as .mp4. Try the same file in an up-to-date browser that reports support, or ask the person who provided it for a version encoded with a codec your browser supports.
The picture plays but there is no sound
The video track may be supported while the audio track is not, or the player may be sending sound to the wrong output. Check whether Browser Info reports the audio codec, then check the player and system audio output.
The codecs appear supported, but playback still fails
The report describes browser capabilities, not whether a particular file is intact or whether a website permits playback. A file can be incomplete or damaged, and protected streaming video can have extra playback requirements. Test another video using the same website or player to see whether the issue is limited to one file.
How to fix video playback
- Reload the page and try again. A temporary player or network error can look like a format problem. If the video is a local file, close and reopen it in the browser.
- Update the browser. Use the browser's menu to find its About or update screen, then install any available update and restart the browser. Newer versions can add or improve media support.
- Install available system updates. On Windows 11, open Settings › Windows Update and check for updates. On macOS, open System Settings › General › Software Update. System media components can affect playback in some browsers.
- Check both audio and video formats. If the picture appears without sound, or sound plays without a picture, the two tracks may use different codecs. Ask for a version with supported codecs for both tracks rather than relying on the file extension.
- Test another video from the same source. If other videos play, the original file may be incomplete, damaged, or encoded with an unusual profile. Download it again from its source if that is safe and allowed.
- Try another browser on the same device. If the video works there, compare the Browser Info results and update the browser that fails. If neither browser plays it, the file or website may be the cause.
Why the file extension is not enough
A container is the wrapper that holds video, audio, subtitles, and other data. Extensions such as .mp4 and .webm usually identify the container, not every encoding choice inside it. For example, an MP4 file might contain H.264 video and AAC audio, while another MP4 might use HEVC video. A browser can support one combination and not another.
That is why a format list cannot promise that every file with a particular extension will play. A supported codec may also be limited to certain profiles or settings, and high-resolution video can be too demanding for a device to decode smoothly. Browser Info is a useful first check, but the result is not a full inspection of a video file.
If the video contains private or sensitive content, use a trusted local player or source when checking it. Do not upload it to an unfamiliar conversion service just to change its format.
