Compress Video
Reduce a video's file size by re-encoding it as MP4 (H.264 video + AAC audio). Pick a CRF — Constant Rate Factor — preset that trades quality for size: 18 is visually lossless, 23 is a balanced default, 28 is heavy compression, and 32 produces the smallest files at noticeable quality cost. Sources taller than 1080p are downscaled to 1080p so browser ffmpeg.wasm doesn't blow its ~2 GB memory budget mid-encode. Encoding is real-time-ish on modern CPUs — a 5-minute 720p clip typically takes 1–3 minutes. The conversion runs entirely in your browser; the file never leaves your device.
Drop .mp4 / .webm / .mkv / .mov / .avi file here
or click to choose
Options
Privacy
Runs entirely in your browser — nothing is sent to any server.
Cost
Free. No sign-up, no watermark.
Supports
.mp4, .webm, .mkv, .mov, .avi → .mp4
Related tools
Tools that work with the same formats — most users open one of these next.
Video Trimmer
Cut a clip from a video file — MP4, WEBM, MKV, MOV, AVI — in your browser.
MP4 to WebM
Convert MP4 video to WebM (VP9 + Opus) — free, runs entirely in your browser.
MP4 to MKV
Remux MP4 to Matroska (MKV) — fast, lossless, no re-encoding.
MP4 to MOV
Convert MP4 video to MOV (QuickTime) — free online, no upload.
MP4 to GIF
Convert MP4 video to an animated GIF — free online, with a tuned palette.
MP4 to MP3
Extract the audio track from an MP4 video as an MP3 file — free online.
Frequently asked
Is Compress Video free to use?
Yes. Compress Video is completely free with no sign-up, no watermark, and no usage limits. Toolsly does not charge for any of its tools.
Do my files and data stay private?
Yes — Compress Video runs entirely in your browser using your device's CPU. Files and text are never uploaded to our servers, so your data stays private.
How does Compress Video work?
Open Compress Video, drop in your MP4, WEBM, MKV, MOV, AVI file, choose any options, and click Convert. Your browser does the work locally and produces a MP4 file you can save right away.
What's the maximum file size for Compress Video?
Because Compress Video runs in your browser, the maximum size depends on your device's available memory. Most modern phones and laptops handle files up to a few hundred MB without issues.