01
Drop your export
MP4 or MOV from CapCut, Premiere, VN — up to 1 GB. We read it instantly and flag what's wrong.
Free · Private · No sign-up
Stop TikTok from
ruining your quality.
You export crisp 1080p or 4K. TikTok uploads it soft and blurry. Kairos fixes your file before you post — in seconds, on your own device — so what you upload is what people see.
1–2stypical fix
1 GBmax file
4K · 120fpssupported
0 uploadsstays on device
From blurry to sharp in 3 steps
No accounts, no waiting room, no quality loss. Just your file, fixed.
02
Pick the right fix
Quick fix repairs order + headers in 1–2s, pixels untouched. TikTok-ready re-encodes to H.264, constant frame rate, ≤1080p — what actually survives upload.
03
Post it sharp
Download your _kairos.mp4 and upload to TikTok like normal. Compare it side-by-side with your old uploads.
BeforeSoft · flat · laggyWrong order, bloated headers, phone struggles to play it back.
After KairosSharp · smooth · readyFast-start order, lean file, plays instantly on upload.
Optimizer
MP4 & MOV · H.264 / HEVC / AV1 passthrough · free & unlimited.
Drop your video here
or click to browse · MP4 & MOV · up to 1 GB
Can't optimize this file.
Your file never leaves this tab. No account, no queue, no watermark.
Recent fixes
Saved in this browser only. Clearing site data removes them.
Analyzer
Check any video: is it fast-start? What's inside? Is it Kairos-verified?
The 60-second export guide
Do this before optimizing — it matters more than any tool.
01
Shoot & edit in the fps you'll post30 or 60, constant — never variable. Mismatched or variable frame rates are the #1 cause of stutter after upload.
02
Export 1080p or higher, high bitrateH.264 High, 12–20 Mbps at 1080p (40+ at 4K), AAC 48kHz. Keep it under 200 MB when you can — huge files get throttled.
Then run it through Kairos, post from the TikTok app, and compare with an old upload. The difference is usually obvious in the first 3 seconds.
Questions, answered.
What does Kairos change in my file?
Two modes. Quick fix: order, not pixels — preview data first, junk removed, QuickTime → standard MP4, verified stamp. TikTok-ready: full re-encode to H.264, constant frame rate, max 1080p, ~12 Mbps — the format TikTok mangles least.
I patched and it still looks bad. Why?
Because TikTok re-encodes every upload, and a container fix can't change that. If your export was variable-frame-rate, 4K, over 25 Mbps, or over 60fps, Quick fix barely changes the bytes — the analyzer says so outright. Use TikTok-ready re-encode for those files.
Will this get me more views?
Honest answer: no tool can promise that. What it does is stop TikTok from mangling your upload on the way in — sharp stays sharp. Views still come from content people watch.
Is my video uploaded anywhere?
No. Everything happens in this tab, on your device. You can watch your network tab while it runs — your video bytes never leave.
Which files work?
MP4, MOV and M4V up to 1 GB. If a file is already optimized, Kairos will tell you to use the original instead of stacking fixes.