Video Compressor
Video files are big, and every platform has a limit: email attachments bounce at 25 MB, Discord refuses oversized clips, and upload forms reject files that are too large. A video compressor re-encodes your video at a smaller size so it fits — and this one runs entirely in your browser.
Unlike most online compressors, nothing is uploaded to a server. The open-source FFmpeg engine loads into your browser tab and shrinks the file on your own device, so private videos stay private and there is no queue, no wait for an upload, and no download-back step.
Choose a quality preset if you just want it smaller, or set an exact target size in MB when you are working against a hard limit — the compressor works out the right bitrate for your video's length automatically.
Powered by FFmpeg (open source) running in your browser — nothing is uploaded.
How to use the video compressor
- 1
Choose your video
Click the upload box and pick an MP4, WebM, MOV, or MKV file from your device. It loads locally in your browser — nothing is sent anywhere.
- 2
Pick a preset or target size
High quality for a slight shrink, Balanced for everyday sharing, Small file for maximum compression — or Target size to fit an exact limit like 25 MB for email.
- 3
Compress and download
Hit Compress and watch the progress bar. When it finishes you see the before/after sizes and can preview and download the compressed MP4.
Why use this tool
No upload — 100% private
Compression happens on your device with FFmpeg in WebAssembly. Your video never leaves your browser, so even sensitive recordings are safe to compress.
Exact target size mode
Working against a 25 MB email limit or a 10 MB upload cap? Enter the MB you need and the tool calculates the bitrate from your video's duration.
Quality presets
Three sensible presets balance picture quality against file size, with sensible resolution caps so small files still look clean.
Before/after proof
You see the original size, the compressed size, and the percentage saved before you download — plus a playable preview of the result.
MP4 output that plays anywhere
Output is standard H.264 MP4 with fast-start enabled, so it plays instantly on phones, browsers, and every sharing platform.
Frequently asked questions
Is my video uploaded to a server?+
Never. The compressor runs FFmpeg inside your browser via WebAssembly. Your file is processed on your own device and never traverses the network — you can even disconnect from the internet after the page loads.
How much smaller will my video get?+
It depends on the source. Screen recordings and camera videos at Balanced typically shrink 50–80%. A video that was already compressed by a platform (like a downloaded TikTok) may only shrink a little — the before/after numbers always show you the real result.
Will compression reduce quality?+
Some quality loss is how compression works — the encoder discards detail your eyes barely notice. High quality mode is nearly indistinguishable from the original; Small file mode trades more quality for size. The preview lets you check before downloading.
Can I compress a video to exactly 25 MB for email?+
Use Target size mode and enter 25 (the quick chips set 25, 10, or 5 MB). The tool computes the bitrate from your video's length; the result lands very close to the target, though not byte-exact.
What's the maximum file size?+
There's no artificial limit, but the processing happens in your browser's memory, so files of a few hundred MB work best. Very large files (1 GB+) can run out of tab memory on low-end devices.
Which formats are supported?+
MP4, WebM, MOV, and MKV inputs all work. The output is always MP4 (H.264 + AAC), the most widely compatible format.
Recording too long as well as too big? Trim it first with our free video trimmer, then compress the clip here.