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Free tool

See exactly what is inside a video file

Container, codecs, resolution, frame rate, bitrate, rotation, channels, sample rate and the tags nobody surfaces. It reads the headers only, so the answer arrives before an upload would have started.

Your file never leaves this tab. It is read, edited and written by your own browser, so nothing is uploaded and nothing is stored.

Why this one

What this tool gets right

Instant, at any file size

Only the container headers and a sample of packets are read, so a four gigabyte file reports as quickly as a four megabyte one.

The fields that explain problems

Rotation flags, coded size versus display size, and whether your browser can decode the track at all. That trio explains most 'why is my video broken' questions.

Measured, not guessed

Frame rate and bitrate are measured from actual packets rather than read off a header that may be wrong.

Copy it as JSON

Copy or download the whole report to paste into a ticket, a spec check or a message to whoever sent you the file.

How it works

Three steps, about thirty seconds

01

Drop the file in

Choose a file or drag it onto the page. It opens straight away, because there is nothing to upload.

02

Set it up

Drag the handles or type exact numbers. The preview applies the same operations in the same order the encoder will.

03

Export and download

Your machine does the encoding, with a real progress bar. The file lands in your downloads folder, unmarked.

What to check when a video will not upload

Platforms reject files for a small set of reasons, and this page shows all of them. Resolution above the accepted maximum. A codec outside the accepted list, usually anything that is not H.264 or HEVC. A frame rate above 60. An audio track that is not AAC. A duration over the limit. A rotation flag that the platform ignores, so the video arrives sideways. Read the report, find which one applies, and the rest of this toolkit fixes it: resize, convert, set the frame rate, or bake in the rotation.

Metadata tags, and what they carry

Containers can hold descriptive tags: title, artist, comment, creation date, and in some files a good deal more. They travel with the file when you share it, and most people never look at them. They are worth a glance before anything goes public. They are also worth knowing about on the way in: exporting through this toolkit copies the source tags across, so a file you got from someone else keeps whatever they wrote in it.

What this tool will not do

  • It will not fetch a video from YouTube, TikTok, Instagram or any other platform. You have to have the file.
  • It will not repair a corrupt or partially downloaded file. If a player cannot open it, neither can this.
  • It will not add anything to the picture: no captions, no logos, no filters. It edits the file you brought.
  • Speed is your hardware. A long 4K clip on a phone will take minutes where a laptop takes seconds.

Questions, answered

Coded size is the pixel grid the encoder actually wrote. Display size is what a player should show after applying the pixel aspect ratio and any rotation flag. They differ on anamorphic footage and on anything rotated, and when a tool ignores the difference you get a squashed or sideways video.
Because it is measured over a sample of packets rather than taken from a header field that many encoders fill in optimistically or leave at zero. For a variable bitrate file there is no single true number, only an average over whatever window you measure.
That the track uses a codec your browser cannot decode, so it will not play here and cannot be re-encoded here either. A container swap that keeps the track as it is may still work.
No. The file is opened by your browser with the File API and rewritten with WebCodecs, the same video machinery your browser uses to play a video. Nothing is sent to a server, so there is no upload wait, no queue and no copy of your file sitting in someone's storage bucket.
There is no limit we impose. The practical ceiling is your machine: the file is read in small pieces rather than loaded whole, so multi-gigabyte sources open instantly, and if you turn on 'write straight to disk' the result never has to fit in memory either. On a phone, expect long clips to be slow.
None of the three. Because the work happens on your machine, this costs us nothing to run, so there is nothing to gate. You get the file you made, unmarked.
Anything current: Chrome, Edge, Safari 17 and up, and Firefox 130 and up. The tools use WebCodecs, so a very old browser will report that it cannot encode, rather than producing a broken file.
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Advibly turns your brand into finished ads: product-in-hand UGC videos, static image ads, carousels, and explainers. Same thinking as this free tool, pointed at the thing that actually takes time.

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