Free tool

Check a video before you post it

Length, frame size, shape, and what each short-video feed does with a file like this one. It opens the file on your own machine and reads it there. Nothing is uploaded, nothing is stored, and you do not need an account.

Drop a video here, or choose one.

Read on your machine - nothing is sent anywhere.

What actually matters in a file

Most upload problems come down to three properties, and only three.

What this tool does not tell you is as important: frame rate, bitrate, codec and whether there is an audio track. A browser cannot read those from a file with any reliability, so rather than print a guess, it prints nothing. If a file will not open here at all, that is itself useful - it usually means an unusual container, and re-exporting as MP4 fixes it.

If it came back wrong

A wide file for a vertical feed cannot be fixed by settings at upload time. Something has to decide which part of the picture survives - and that decision is the difference between a clip that looks made for the phone and one that looks borrowed. What a wide recording loses going vertical shows what that costs and what a good version looks like.

A file that is too long has the opposite problem: nothing is wrong with it except that it keeps going. How long a clip should be covers the trade, and why a short gets no views covers what else stops a technically perfect file.

SnapDub handles both in one pass: it picks the moments out of a long recording, reframes each one onto whoever is speaking and burns in captions, and hands you clips that are already the right shape and length for the feeds you are posting to.

If the file needs work

Turn the recording into clips that fit

Start free with 500 credits a month - no card required.

Start clipping free
About this tool

Questions about the checker

Is my video uploaded anywhere?

No. The file is opened by your own browser and read there. It is never sent to us or to anybody else, there is no account, and nothing about it is stored.

What aspect ratio should a TikTok, Reel or Short be?

9:16 - taller than it is wide, typically 1080 by 1920. That fills a phone screen completely. Square works everywhere but uses less of the screen, and anything wider than it is tall gets black bars above and below.

Why does my video have black bars?

Because it is a wide frame in a tall feed. The app cannot crop for you, so it pads instead. The only real fix is re-framing the picture for a vertical screen before you upload it.

What is the maximum length for a Short or a Reel?

Three minutes for both as of September 2026. Longer uploads still work, they just stop being treated as a Short or a Reel and leave those feeds.

Why can this tool not tell me the frame rate or the codec?

Because browsers do not expose them reliably, and a number that is wrong some of the time is worse than no number. Everything shown here is read the same way by every browser.

The file will not open in the checker at all. What does that mean?

Usually an unusual container or codec, which is often the same reason a platform rejected it. Re-exporting the video as MP4 with H.264 video resolves nearly every case of this.