How to use the Video Codec Checker tool
- Choose your video file.
- The answer appears at the top of the card.
- Scroll for the full details: file, video and audio.
- Copy as text or download the JSON if you need to share it.
About this tool
Which codec a video uses decides where it will play. This tool reads the codec string from the file, decodes the profile and level for H.264, and tells you whether your own browser can decode it.
Reading is instant because only the file's index is parsed, not the video itself: even a multi-gigabyte file answers in a moment. You can copy everything as text or download it as JSON, which is handy for bug reports and support tickets.
Why use ToolsCrow for this
- Instant. Only the index is read, not the whole file.
- Complete. File, video and audio details in one place.
- Copy or export. Plain text or JSON.
- Private. The video is never uploaded.
Good to know
- It reads MP4, MOV, M4V, WebM, MKV, 3GP and FLV. Browsers cannot open AVI, WMV or MPEG files, so those cannot be inspected here.
- It shows what the container declares. Specialist tools such as MediaInfo or ffprobe report more, for example colour space and HDR metadata.
Frequently asked questions
Is my video uploaded to a server?
No. Everything runs inside your browser tab using your own device's video hardware. Your file is never sent to ToolsCrow or anyone else, which also means there is no waiting for an upload and it keeps working if your connection drops after the page has loaded.
Is it really free? Is there a watermark?
It is free with no sign-up, no watermark and no daily limits. The only limits are the ones your device sets: memory and processing power.
How large a video can I use?
Because the video is processed on your device, the limit is your device's memory rather than a server quota. Phone clips of several hundred MB are fine on most devices, and desktop computers usually handle 1 to 2 GB. Files over about 4 GB are not supported.
Which browsers work best?
Current Chrome, Edge and Safari (16.4 or newer, including iPhone and iPad) work best because they include the WebCodecs video engine. Recent Firefox versions work for many files. Older browsers fall back to a much slower real-time mode or may not work at all.
Why does my video not play on some devices?
Usually the codec. HEVC (H.265) is common on iPhones and plays on Apple devices but not everywhere else; AV1 and VP9 need newer players. Converting to H.264 MP4 fixes almost all playback problems.
Is my video uploaded to check it?
No. The file is read directly in your browser, and only the first part of it is needed.
Does it work with large files?
Yes. Only the index is read, so a 4 GB file is as fast as a small one.
Related video tools
- Video InfoDrop in a video and see the answer straight away.
- Check Video ResolutionDrop in a video and see the answer straight away.
- Video Duration CheckerDrop in a video and see the answer straight away.
- Video Frame Rate CheckerDrop in a video and see the answer straight away.
- Video ConverterConvert a video to MP4, WebM or MOV without uploading it anywhere.
- Video CompressorShrink any video to a fraction of its size while keeping it sharp, or type the exact size you need in MB.
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