Drop a video or audio file
MP4 · MOV · WebM · MKV · MP3 · WAV — read locally, never uploaded · handles multi-GB files
Drop a video, get the full spec sheet — and the reason it won't play somewhere.
Your files never leave your browser — all processing is local.
Drop a video or audio file
MP4 · MOV · WebM · MKV · MP3 · WAV — read locally, never uploaded · handles multi-GB files
Drop an MP4, MOV, WebM, MKV, MP3 or WAV file and this inspector reads its metadata in seconds — only the structure is parsed, not the whole file decoded, so even multi-gigabyte files respond instantly and nothing is uploaded. You get the container story (format, duration, overall bitrate, track list) and, per video track, the codec string translated into plain language — avc1.640028 becomes "H.264 High Profile, Level 4.0" — plus resolution, frame rate (declared and sampled), bit depth, rotation metadata (the invisible reason phone videos display sideways) and HDR color info.
Its killer feature answers the question that brings people here: "why won't my video play?". Each track is checked against your current browser's actual decoding support, producing a playability verdict — and a matrix of typical support across Chrome, Safari and Firefox highlights moves like HEVC-in-Safari-only. The faststart check reads whether the MP4's moov box sits at the head or tail of the file: tail-parked metadata is the classic reason a web video buffers forever before starting, and almost no online tool checks it.
A bitrate timeline chart samples packet sizes across the duration — spikes are your stutter suspects — alongside first-frame thumbnail and keyframe-interval (GOP) statistics that matter for streaming latency. The whole report copies to the clipboard as plain text for forums, issue trackers or support tickets.
Two extras make it a working tool rather than a read-out. Load a second file to compare two videos side by side in aligned columns, with every differing field — codec, resolution, frame rate, bitrate, HDR, faststart, GOP — highlighted so a re-encode's real effect is obvious at a glance. A keyframe distribution strip plots every key frame along the timeline and flags GOPs whose length strays from the median, exposing scene-cut and variable-rate keyframes that hurt seeking. When you're done, contextual links hand the same file straight to our GIF and PNG-frame converters.
No. The file is parsed structurally in your browser — headers, track tables and packet indexes are read via random access, the media itself stays untouched on disk. That's why a 4 GB file opens in about a second and why there is no size limit.
Usually the codec: HEVC/H.265 (common from iPhones and drones) has no Firefox support and patchy Chrome support, while desktop players decode almost anything. The playability matrix shows which of your file's tracks each browser family can decode, turning "it just doesn't work" into a specific codec verdict — and the fix is typically re-encoding to H.264 or converting in our video tools.
MP4 metadata lives in a "moov" box that can sit at the file's head or tail. Encoders default to writing it at the tail; browsers need it before playback, so a tail moov forces the whole file to download before a web player starts. The check reads where yours is and tells you when a remux (fast, lossless) would fix slow web starts.
Phones often record sensor-native video and store a rotation flag in metadata rather than rotating pixels. Players that honor the flag display correctly; pipelines that ignore it show sideways video. The inspector surfaces the rotation value so you know the flag — not the pixels — is what needs fixing.
Per-second data rate across the video. A flat line streams predictably; big spikes (action scenes, confetti, camera pans) are where underpowered connections or players stutter. It also verifies whether a "10 Mbps" export really averages 10 Mbps.
Yes — hit "Compare with another file", drop a second video, and both analyses line up in one table with every differing field (codec, resolution, frame rate, bitrate, HDR, faststart, GOP) highlighted. It is the quickest way to confirm what a re-encode actually changed, or to see why one export plays and a near-identical one does not.
One tick per key frame along the video's timeline. Evenly spaced ticks mean a fixed GOP that seeks predictably and starts streaming quickly; orange ticks mark key frames whose spacing strays from the median — scene-cut or variable-rate keyframes that can make scrubbing feel uneven and inflate streaming start latency.