File header reader
What the file says it is, in plain words.
Drop in a file and see what its header says: container, codec, resolution, frame rate, scan, bit depth, chroma, colour tags, audio tracks and start timecode, with a note wherever it contradicts a published standard. The file is read in your browser; nothing is uploaded.
Drop a file, or click to choose
MOV, MP4 or MXF (OP1a or OP-Atom). Only the header is read. Nothing is uploaded.
What a header can’t tell you
This reads container metadata only. These need a full decode:
- •Loudness (LUFS) & true peak: Requires decoding and measuring the full audio. Measure it with the loudness meter.
- •Track layout & channel content: Silent or copied tracks, dual-mono pairs, Dolby E placement and 5.1 order need the audio itself. Check it with the track layout verifier.
- •HDR metadata (mastering display, MaxCLL, Dolby Vision): Whether the HDR metadata is consistent across container, bitstream and sidecar. Check it with the HDR metadata checker.
- •Super-black, super-white & gamut: Codes outside the legal range and out-of-gamut colour are in the pixels, not the header. Measure it with the signal range checker.
- •PSE / flash & pattern risk: Frame-by-frame luminance analysis; not in the header.
- •GOP structure & compliance: Needs bitstream inspection, not container metadata.
- •Subtitle timing & reading speed: Depends on the caption payload, not the wrapper.
- •Package & structure (AS-11 DM, sidecars, checksums): Whole-deliverable checks beyond a single file’s header.
- •Actual colour vs signalled: Flags may be present but wrong. Only measurement confirms.
- •Blanking, AFD, freeze/black frames: Pixel-level checks that a header can’t see.
A header check is a first pass, not a QC
Reading a file’s container tells you the structural facts quickly and for free: the resolution, whether it’s interlaced, 8-bit or 10, how many audio tracks it carries. A header can be wrong (colour flags that don’t match the pixels) and it says nothing about what’s actually in the frames or the audio.
Loudness, true peak, PSE/flash risk, GOP structure, subtitle timing and whole-package structure all need the file decoded and measured, which no header can stand in for. For loudness and true peak, drop the same file into the broadcast loudness meter; for the bars-and-tone leader at its head, the line-up checker.
Header parsing by MediaInfo (BSD), compiled to WebAssembly and running entirely client-side.
Related: checksum manifest builder & verifier · video file size calculator · QC notes & marker converter · segment timing checker (black, silence, part breaks).