Check a Video's Codec, Frame Rate, and Bitrate Online — Without Uploading It (2026)

To find out what is actually inside a video file — container, video and audio codecs, resolution, real frame rate, duration, bitrate, channel layout — you do not need to install anything or upload the file anywhere. The free Media Probe reads the file on the page, in your browser: open the file, get the report, copy it as text or download it. The file itself never leaves your machine, which also means a 2 GB clip is inspected in seconds instead of uploading for minutes.

Here is why the filename cannot be trusted, what the report tells you, and the four findings that save the most debugging time.

Why the filename lies

.mp4 is not a codec. It is a container — a box that carries video streams, audio streams, and metadata. What is inside the box varies wildly: the video stream might be H.264 (plays everywhere) or HEVC (choosier), AV1 or VP9; the audio might be AAC, or missing entirely.

That gap between the box and its contents is where whole categories of confusion live:

• "It's an MP4, why won't the editor open it?" — because the codec inside is the problem, not the extension.
• "The upload was rejected but it plays fine locally" — platforms restrict codecs and bitrates, not extensions.
• "A file someone renamed from .mov to .mp4" — the name changed; the container did not.

A probe answers the question the filename cannot: what is actually in there? The report comes from parsing the container itself, so you get real values instead of whatever the file is named.

What the report contains

Open a video or audio file on the Media Probe page and you get a structured report:

• Container — the actual box format, regardless of extension
• Video codec — H.264, HEVC, VP9, AV1…
• Resolution — including what the rotation flag does to it (more below)
• Frame rate — the measured value, and whether it holds steady
• Duration and bitrate — is this file plausibly sized for its length and quality?
• Audio — codec, sample rate, channel count, or the finding that there is no audio track at all

The report can be copied as plain text or downloaded — made for pasting into a support ticket, a client email, or your own notes when a file misbehaves.

Four findings that save the most time

1. HEVC — plays on your phone, chokes elsewhere

Recent iPhones record HEVC (H.265) by default. It is efficient, and it is also the single most common answer to "why does this file not open on my Windows machine / in my browser / on this platform?" Knowing the codec before you build a workflow around a file turns a mystery into a plan: transcode it once, or keep it and accept where it will not go.

2. Variable frame rate — the silent audio-drift maker

Screen recordings and phone footage often have a variable frame rate (VFR): instead of a steady 30 frames every second, the spacing between frames wobbles with load. Many editors quietly assume constant frame rate, and the classic symptom is audio drifting out of sync, getting worse the longer the clip runs. The probe flags VFR so that when you see drift, you already know why — and can conform the clip to a constant rate before editing instead of chasing ghosts afterward.

3. Rotation flags — why "vertical" video is secretly horizontal

Phones usually record sensor-native landscape and set a rotation flag telling players to display it turned. Tools that ignore the flag show your portrait clip sideways; tools that respect it disagree with tools that do not. When a video displays rotated somewhere, the probe shows you whether a flag is present — which is the difference between "the file is broken" and "one tool ignores rotation metadata".

4. No audio track

A surprising number of "the export has no sound" bugs start with a source file that never had audio in the first place. Ruling that out takes one probe and zero debugging.

How to check a file, step by step

1. Open /tools/media-probe/ in any modern browser — nothing to install.
2. Open your video or audio file on the page. It is parsed locally; nothing is uploaded, and the file never enters any timeline.
3. Read the report — codecs, resolution, frame rate, bitrate, channels, plus flags for the gotchas above.
4. Copy the report as text or download it if it needs to travel to a ticket or a teammate.

Costs just 1 credit on Free (from 100 monthly credits; included with Pro), with zero upload and no file-size anxiety — inspection happens at local disk speed.

When the file checks out, the next steps are on the same site

The probe is one of Beat2Cut's standalone inspection tools, next to the loudness check (peak, average level, and a rough loudness estimate before delivery — honestly labeled: not a certified broadcast meter) and the contact sheet (one timecoded PNG grid of frames to scan a whole clip at a glance).

And when the file is healthy and it is time to actually cut it: the Studio timeline provides unlimited beat detection, scene and silence detection at 2 credits each, exports cut lists for Final Cut Pro, Premiere, and Resolve (free for beats, 2 credits for shots on Free), and delivers a merged MP4 for 10 credits on Free (all included with Pro).

FAQ

Is this an online version of a media-info tool?

Same job, different plumbing: it reports what is genuinely inside a media file. The difference is that the analysis runs in your browser on the local file — there is no upload step, no server-side queue, and no size-limit tied to a hosting quota.

Does the file really not get uploaded?

Correct — the probe parses the file on the page. That claim is scoped to these inspection tools and to detection/editing/export in the Studio: those steps process source media in the browser. (Features that are inherently online — account sign-in, AI narration — say so explicitly and involve script text, not your media files.)

What formats can it read?

The common containers for video (MP4, MOV, WebM, M4V) and audio (MP3, WAV, M4A, AAC), covering codecs like H.264, HEVC, VP9, and AV1 on the video side.

My editor says 29.97 fps but the probe suggests variable frame rate — who is right?

Both, in a sense: many tools display the average rate. A VFR file can average 29.97 while individual frame gaps wobble around it — which is exactly the case that causes audio drift. Treat the VFR flag as the actionable fact.

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Check the file first: open the Media Probe — thirty seconds of reading beats an afternoon of debugging a mystery file.