Compress Video Online — Reduce MP4 Size in Your Browser
Compress video online for free right in your browser. Reduce MP4, MOV, WebM and MKV size with H.264 — no upload, files stay on your device.
MP4, MOV, WebM, MKV
Drag and drop your file here or click to select
About compressing video online
This tool compresses your video entirely in your browser using ffmpeg.wasm. The clip is re-encoded to efficient H.264 (MP4) on your own device, so nothing is ever uploaded to a server — the file never leaves your computer or phone.
Pick one of three levels: Light keeps quality close to the original, Balanced is the everyday choice, and Strong squeezes the file as small as possible. Larger videos are downscaled to 1280 px on the long side, which is perfect for sharing in messengers, attaching to email, or posting on the web.
Because everything runs locally, your video stays private. On the first run the browser downloads the ~32 MB compression engine once, then caches it — every compression after that starts instantly.
When it helps
Send video in a messenger
WhatsApp, Telegram and iMessage cap attachment size. Shrink a clip so it sends without failing or losing quality to their own re-compression.
Shrink video for email
Most inboxes reject attachments over 20–25 MB. Compress a long recording down to a size that actually goes through.
Free up storage
Re-encode bulky phone or screen-recording videos to H.264 and reclaim space on your device or drive without deleting the footage.
Upload to a site faster
A smaller MP4 uploads to a form, CMS or portfolio in a fraction of the time and stays under file-size limits.
FAQ
How do I compress a video online for free?
1) Drop your MP4, MOV, WebM or MKV file onto the page. 2) Choose a compression level — Light, Balanced or Strong. 3) Click "Compress video" and download the smaller MP4 when it's done. It's free with no sign-up and no watermark.
Is my video uploaded to a server?
No. The whole process runs in your browser with ffmpeg.wasm, so the video is compressed on your own device and is never sent anywhere. This works even if you go offline after the page has loaded.
How much smaller will it get?
Usually 3–10× smaller, depending on the level and the original file. Strong on a high-bitrate phone clip can cut it by 8–10×; Light on already-optimized footage gives a more modest reduction.
Which formats are supported?
You can load MP4, MOV, WebM and MKV files. The output is always an MP4 encoded with H.264, which plays on virtually every phone, computer and website.
Why is the first run slow?
The first time you use the tool your browser downloads the ~32 MB compression engine. That happens once and is then cached, so every later compression starts right away.