CoMBress
Compress a paper supplementary video to a conference upload cap.
Enter the portal's MB limit, save an H.264 MP4 under the cap. Your video stays in this browser.
Use the exact limit shown by CMT, OpenReview, or IEEE.
How to verify local processing
- Encoding runs on ffmpeg.wasm (open-source ffmpeg) inside this tab.
- On first compress the engine downloads once (~30 MB); after it has loaded you can disconnect and keep compressing.
- Watch your browser's Network tab: your video file is never sent.
The page and engine load from a CDN, and unlocking a license contacts Polar — your selected video file is never uploaded. Close the tab and the working data is gone.
Built for submission deadlines
- One job: get a supplementary video under a portal's MB cap — not a general-purpose compressor.
- Keeps your resolution when the bitrate fits; downscales only when the cap is tight.
- Runs locally, so it's safe for unpublished and double-blind material.
- Exports a reviewer-friendly H.264 MP4 that plays wherever it's opened.
Works with the CMT, OpenReview and IEEE upload systems used by venues like CVPR, ICCV, ECCV, NeurIPS, ICLR, CHI, SIGGRAPH, 3DV and ISMAR. (Not affiliated with these venues.)
Pricing
Free: 3 full compressions, no sign-up — then $9 one-time for unlimited.
Sold by Forschken via Polar (Merchant of Record). Your card statement shows “Forschken.”
FAQ
Is my video uploaded?
No. Compression runs as WebAssembly inside this tab — your video is read, re-encoded, and saved entirely on your own machine, so it stays safe for double-blind review and unpublished work. The page loads from a CDN and unlocking a license contacts Polar, but your video file is never sent anywhere.
Will it fit under the cap?
Yes. It aims a little under your cap (a safety margin), so the result lands below the limit rather than exactly on it. For tight caps it lowers resolution to fit, keeping the original resolution whenever the bitrate allows. If a cap is physically too small for the clip's length, it tells you how short to trim instead of failing silently.
What format do I get?
An H.264 MP4 with AAC audio and faststart enabled — the most broadly compatible combination for reviewers, so it plays wherever it's opened.
What if the file is too large?
It works best for typical supplementary clips. Very long or high-resolution videos are slower and bounded by your browser's memory, since the encoder runs locally — the tool warns you before starting. Re-export an H.264 proxy if a clip won't process.
How does pricing work?
The first 3 compressions are free, no sign-up. After that a one-time $9 license key unlocks unlimited use — no subscription, no account. Activate the key in any browser you use, and keep it to re-activate if you switch machine or browser. Combress is sold by Forschken via Polar (Merchant of Record), so your receipt shows “Forschken.” Your video never goes to Forschken or Polar.