How to Compress a Video for TikTok

The fastest way to compress a video for TikTok is to check the file size against the platform's actual ceiling first, then reduce the frame before the bitrate, and re-encode only once. Here's the full pass, and the numbers TikTok publishes.

Compress a video for TikTok: the ceilings that exist

There are two published limits and they're a long way apart.

TikTok's Content Posting API documentation gives a maximum file size of 4GB. That's the technical ceiling, and ordinary phone footage rarely approaches it.

TikTok's advertising specifications are far tighter: a file size of 500 MB or less, and a bitrate of at least 516 kbps. That's the number worth planning around if you're running paid creative, and it doubles as a sensible informal target for organic posts. A clip that comfortably fits inside 500 MB will upload quickly and re-encode cleanly.

Note the bitrate line is a floor, not a cap. Compression that drops below it produces a file that's technically small and visibly poor.

The three levers, in the order worth pulling them

File size is frame size, frame rate and bitrate multiplied together, and they don't cost the same.

Frame size is the cheapest saving: pixels the feed never displays are pure waste, and taking an oversized frame down to a vertical 1080-wide one can halve the file before anything visible changes. Frame rate is the next lever, and it's the one that costs most in feel, motion goes first. Bitrate is last, because that's where blocking and mush live.

The rule underneath all three: compress once. Every additional pass discards detail that no later step can recover, so the compression belongs at the very end of the edit, applied to the best source you have.

One export, in an efficient codec

Montaj exports at 1080x1920 in HEVC (.mp4), and HEVC is the more efficient of the two codecs a phone typically produces. The same picture in fewer bits than H.264. There's no bitrate slider to guess at, because there's one export target. The render happens on your device, so no version of the file is uploaded to be processed. Compressing a video for TikTok is much less of a problem when the export was sized correctly to begin with.