video
How to inspect video codec and container information
MP4 is a box. H.264 is a payload. The extension names the box.
By ConvertPass. Last reviewed 16 August 2026.
What the browser knows
An HTML video element can often tell you duration, width, and height after metadata loads. It often cannot tell you a clean codec string. MediaInfo and ffprobe can. A website pretending to be ffprobe would lie a lot.
ConvertPass’s inspector reports what it can and estimates bitrate from size and duration. That estimate is labelled as an estimate.
What we tested
Capability detection is ‘can this browser fire loadedmetadata on this file’. A codec it cannot demux fails with a useful error, not a spinner forever — you can cancel.
When you need more
Use ffprobe locally for codec names, colour range, and audio layout. ConvertPass is the privacy-first first look, not a replacement for a desktop analyser.
Related tools
- Video file inspector
Read duration and resolution from a video without uploading it.
- Video bitrate calculator
Turn file size and duration into an estimated bitrate, locally.
- Video compressor
Auto-compress a short clip locally to MP4 or WebM, using this browser’s encoder.
Related guides
Related formats
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