Too big to upload? Make it smaller.
Pick the size to stay under. The bitrate that lands there is worked out from the video's length, and your browser re-encodes it — no upload, no watermark.
Runs in your browser. Nothing is uploaded, no signup.
Watch an example
13 seconds · a made-up example
Videos made in the studio come out ready to upload: vertical H.264 + AAC MP4.Join the beta
How it works
Short and checkable: every limit links to the platform's own page, read on 28 Oct 2026.
The size sets the bitrate
Size × 8 ÷ length gives the bits a second the file can carry; the sound keeps 128 kbps and 4 % is left for the file's own overhead. The rest goes to the picture.
A smaller picture often looks better
At the same size, a 720p picture gets twice the bits per pixel of a 1080p one. If the bitrate falls under about 2 Mbps, try 720p.
Encoded by your browser
WebCodecs, the browser's own H.264 encoder, does the work; Mediabunny reads the file and writes the new MP4. Nothing is sent anywhere.
What it doesn't do
- It doesn't do two-pass encoding like ffmpeg: the size lands close under the target, not to the byte.
- Very long or 4K files can take minutes and need memory; the new file is kept in this tab until you save it.
- HDR videos come out in standard range.
Questions
How do I compress a video for Instagram?
Instagram's API takes Reels up to 300 MB. Drop the video, keep 300 MB as the size and 1080p as the picture size; the tool works out the bitrate that lands under it and re-encodes the file in your browser as H.264 and AAC.
Does compressing lower the quality?
A little: a smaller file has fewer bits per frame. Lowering the picture size (1080p to 720p) at the same file size often looks better than squeezing a 4K picture.
Is my video uploaded to compress it?
No. Your browser's own encoder (WebCodecs) does the work in this tab. A long 4K video can take a few minutes on a slow computer.
Sources
- 1Meta for Developers — Instagram API — IG User Media, Reel specifications and captionAPI v26.0 · read 28 Oct 2026
- 2Mediabunny — Mediabunny 1.61.4 — reads and writes video files in the browserMPL-2.0; downloaded by your browser · read 28 Oct 2026
- 3MDN Web Docs — WebCodecs API — the browser's own video encoder and decoderChrome, Edge, Safari 17+; Firefox 130+ · read 28 Oct 2026
More free tools
All 25 tools- Make the videoShort video analyzerWhy does this short work?
- Make the videoScript timerHow long will this script run?
- Make the videoAuto subtitlesNo subtitles yet? Make them here.
- Make the videoVideo to textNeed the words of a video as text?
- Make the videoBurn subtitlesSubtitles that stay on TikTok and Reels?
- Make the videoSubtitle checkerCan people read your subtitles in time?
Compressing is one step. The studio makes the whole video.
Vertiscale writes, voices and edits each video, renders it in the right size for every platform, and publishes it to each of your accounts.