Video Codec Identifier
Local, best-effort inspection. Your video stays in this browser.
What the codec identifier tool reads
The tool inspects the first 4 MB for file signatures and common stream tags. ISO Base Media files expose an ftyp box. Matroska and WebM begin with EBML bytes. Tags such as avc1, hvc1, hev1, av01, and vp09 can identify common video streams.
That is enough for a fast local clue. It is not a full demuxer, and the result says “best effort” on purpose.
MP4, WebM, or MKV holds streams and timing data. The extension usually names this outer layer.
H.264, HEVC, VP9, or AV1 describes how the video stream was compressed and must be decoded.
Privacy and file handling
The selected file remains on your device. JavaScript reads a small slice through the browser File API. There is no form submission or upload endpoint in this tool, and the selection is forgotten when you close or reload the tab.
Files up to 2 GB can be selected because only the header slice is read. A malformed file should still be treated as untrusted input; the browser’s byte reader receives it, while no native decoder is invoked by the inspector itself.
Explain the results
- Container describes the outer structure, such as ISO Base Media or Matroska/WebM.
- The video codec tag may indicate AVC/H.264, HEVC/H.265, AV1, VP9, VP8, or Theora.
- Audio codec uses a separate stream. AAC, Opus, Vorbis, AC-3, and E-AC-3 are common examples.
- Browser file type comes from the operating system or browser and can be blank or wrong. It is not treated as proof.
Profile, level, bit depth, dimensions, frame rate, duration, and precise bitrate require deeper parsing than this first release promises. For those fields, open the file in MediaInfo.
Common files the tool can expose
An MP4 containing HEVC often carries hvc1 or hev1. An MP4 containing H.264 commonly exposes avc1. WebM may contain VP9 or AV1 and Opus audio. An .mp4 extension on an MKV file can be caught by the signature mismatch.
Multiple video streams, late metadata, encrypted media, and fragmented containers can defeat simple tag scanning. A missing tag means “not found in the inspected slice,” not “this file has no video.”
Finding the bitrate of a video
A full parser may report stream bitrate directly. When it does not, use total file size and duration to estimate average total bitrate:
average total bitrate = file size in bits ÷ duration in seconds
Then subtract audio and allow for the container. The Video Bitrate Calculator performs that relationship in both directions.
How to check bitrate of video accurately
Variable bitrate files have peaks and valleys. A single average cannot describe their highest decode or network demand. MediaInfo can show an average, while tools such as FFprobe expose individual streams and more technical metadata.
Link inspection to the next test
| Detected result | Next action |
|---|---|
| HEVC / H.265 | Run the HEVC browser test |
| HEVC fails in Chrome | Use Chrome H265 troubleshooting |
| Local HEVC playback needed | Follow HEVC VLC steps |
| Browser reports unsupported format | Diagnose format and MIME failures |
| Bitrate planning needed | Open the Video Bitrate Calculator |
Identification describes the file. The playback test checks one real browser path. Keep those jobs separate and the diagnosis stays much cleaner.
Limitations
Metadata can be absent, misleading, encrypted, or placed later in the file. Average bitrate hides peaks. Browser APIs expose less than desktop analyzers. A codec name alone cannot prove hardware decoding, smooth playback, HDR output, or audio support.
For an important production decision, confirm this quick result with MediaInfo or FFprobe and test the exact output on the target devices.