Compress video for Instagram
Big exports from CapCut or your phone make Instagram uploads crawl. Slimcast shrinks your Reel or feed video to a smaller size right here in your browser, so it uploads faster and processes sooner. Nothing is uploaded to a server first — your video never leaves your device.
Frequently asked
Instagram compression, answered
Does Instagram have a file-size limit for videos?
There's no small mandatory cap for normal feed posts or Reels. Instagram re-encodes everything on upload, so the main reason to compress is speed: a smaller file uploads faster and finishes processing sooner. Slimcast lets you pick a target size and lands your video just under it.
Will compressing hurt my Reel's quality?
Instagram re-compresses your video on its end no matter what, so a sensibly sized H.264 MP4 looks essentially the same after upload. Starting from a smaller, clean file often gives you a better final result than pushing a giant export through Instagram's pipeline. Pick a higher target if you want more headroom.
My CapCut export is huge. Can Slimcast shrink it?
Yes. CapCut and similar editors often export very large files. Drop the export here and choose a target in MB — Slimcast computes the right bitrate from the clip's duration to hit that size on the first try, and outputs a web-optimized MP4.
Is my video uploaded anywhere?
No. Compression runs entirely in your browser through ffmpeg.wasm. Your video never leaves your device — no upload, no server, no account. Works best in a Chromium-family browser over HTTPS.