Compress video for Signal
You chose Signal for privacy — don't upload your videos to a random compressor site to shrink them. Compress 100% on your device: nothing ever leaves your browser.
Drop your video here
or
MP4, MOV, WebM… — processed 100% on your device
Target size
Planned output:
ð¦ Large file: encoding several hundred MB in your browser can take a very long time, and phones may run out of memory. Desktop Chrome recommended.
Loading encoder…
🔒 Your video never leaves your device. No upload, no signup, no watermark.
Shrink it for Signal in 3 steps
Drop your video in — privately
Drag and drop your clip into the tool above. Everything runs on your device, so a private video stays private — nothing is uploaded anywhere.
Target 20 MB
The 20 MB preset is pre-selected — a safe default that sends quickly and keeps quality high.
Share on Signal
Download the result and attach it in Signal. Your video was never uploaded anywhere, so it stays as private as the chat itself.
The private way to shrink a video
Most “compress video online” tools make you upload your footage to their servers first. If you care enough to message on Signal, that tradeoff makes no sense. VidSizer runs the encoder (FFmpeg, via WebAssembly) inside your browser tab — your video is never transmitted, stored, or seen by anyone.
Signal caps attachments well below what modern phone cameras shoot, so compression is unavoidable. Do it here, then send — the private part stays private end to end.
Need a different target? Compress to 10 MB · Compress to 20 MB · Compress for WhatsApp
FAQ
How do I compress a video for Signal?
Drop your video above and hit Compress. Everything runs locally in your browser — pick any exact target size, get a verified file back, then attach it in Signal.
Why does on-device matter for Signal users?
Server-side compressors receive a full copy of your video. With VidSizer the bytes never leave your machine, so the privacy Signal gives your messages extends to the compression step too.
What size should I target for Signal?
20 MB is a safe default that sends quickly. If Signal still resists, step down to 10 MB or 8 MB — the tool shows its planned output before encoding.