Check a Video’s Codec Online

How to check video codec online in a single drop

Drop the file above and read the card. That is the whole job, and it takes about two seconds on a normal clip.

Nothing is uploaded. We read the container in your browser, which matters for video more than for most file types — a single clip can be several gigabytes, and sending it somewhere to learn one word about it is a poor trade.

The catch is that we can only read files you already have. A video streaming from a service is not a container you can inspect, and no browser tool can change that.

Reading a video bitrate checker without fooling yourself

Bitrate is data per second, and people treat it as a quality score. It is not one.

How well those bits are spent depends entirely on the codec and the encoder behind it. A carefully encoded H.265 file at 8 Mbps regularly beats a rushed H.264 at 15. Comparing bitrates across different codecs tells you almost nothing useful.

The comparison that does work is like for like. Same codec, same resolution, same content — then a higher bitrate genuinely means more detail retained. We show the video bitrate and the overall bitrate separately, because the gap between them is audio and container overhead, and a wide gap usually means extra tracks you had not spotted.

So what resolution is my video, actually?

Usually exactly what the card says. Occasionally the number surprises people, and there are two honest reasons for that.

The first is anamorphic storage. Some footage stores non-square pixels and carries a separate display aspect ratio, so the stored width is narrower than the width you see on playback. Nothing is broken; the player stretches it back.

The second is rotation. Phones record in one physical orientation and add a rotation flag rather than rotating the pixels, so a portrait clip is often stored as landscape. Editors that ignore the flag show it sideways, which is a support ticket rather than a fault.

Using a frame rate checker online before you start cutting

This is the field with the sharpest consequences and the least attention.

Screen recorders, phones and OBS often write variable frame rate footage, where the rate rises and falls to save space. Premiere and Resolve both cope badly with it, and the symptom appears late: audio that starts in sync and drifts apart over ten minutes.

We flag the mode on the card. If it reads variable, transcode to a constant rate before you build the timeline rather than after you notice the drift. There is a dedicated constant or variable frame rate test that answers only that question and explains the fix.

Watch the decimals too. A rate of 29.970 is not 30, and mixing the two on one timeline produces slow drift that nobody notices until the export.

A MediaInfo alternative in the browser, and where it stops

The engine here is MediaInfo, compiled to WebAssembly and served from our own domain. It is the same library the desktop application uses, so the readings agree.

What you gain is not having to install anything, and not having to hand a file to a server. What you give up is real. Desktop MediaInfo shows a full tree with hundreds of fields, batch processing and export templates. This page shows six numbers on purpose, because six numbers answer the question most people arrive with.

If you want the whole field list instead, our video metadata viewer renders every track and every tag, including duplicate audio and subtitle streams that most operating system property panels hide.

Which fields matter for the job you are doing

Different problems point at different rows on that card.

A file that will not play is nearly always the codec or the profile. High 10 means 10-bit colour, which plenty of older televisions and phones simply refuse. Working out whether a file is H.264 or H.265 solves most of these in one step.

A render that came out too large is bitrate and codec together. Look at the video bitrate rather than the file size, because duration hides the real setting.

Stuttering playback on an otherwise capable machine usually means hardware decoding is not engaged, which comes back to the codec and profile pair.

Audio that slides out of sync is the frame rate mode, every time.

Check the codec before you commit the render

Two seconds up front beats an hour of exporting into the wrong format. Check the codec online before you import footage, before you send a file to a client, and before you queue an overnight render.

Once you know what you have, the rest follows. Our video compressor handles a file that is too large for an upload limit, and converting the format fixes one a device refuses to open. If the concern is what the file says about you rather than how it plays, whether videos store GPS is the place to start, and you can remove metadata from the video without touching a single frame. For the full field list behind all of it, what video metadata is walks through every tag a container can hold.