Free tools · Compress & resize
Fit to aspect (add bars)
Fit a whole video inside a new aspect ratio — 9:16 for Reels, 1:1 for feeds, or 16:9 — by adding clean bars instead of cropping. Choose black or white bars. Runs in your browser.
Runs entirely in your browser. Your file is never uploaded — no watermark, no account.
How to use Fit to aspect (add bars)
- 1
Choose your file. Drop a file into the tool, or click to select one. It stays on your device — nothing is uploaded.
- 2
Pick your settings. Adjust the options if you like, then press Run. The first run downloads a ~32 MB engine once; after that it's instant.
- 3
Download. Everything is processed right in your browser — download the finished file instantly, with no watermark.
Frequently asked questions
- Is Fit to aspect (add bars) free? Is there a watermark?
- Yes — Fit to aspect (add bars) is completely free, with no sign-up, no watermark, and no limit on how many files you process.
- Do my files get uploaded to a server?
- No. Fit to aspect (add bars) runs entirely in your browser with WebAssembly, so your MP4, MOV, WebM, MKV file never leaves your device and nothing is stored or seen by us.
- What can I put in, and what do I get out?
- Fit to aspect (add bars) accepts MP4, MOV, WebM, MKV and gives you back a MP4 file. You can also set aspect ratio and bar colour before you run it.
- Can I control the output?
- Yes — you can adjust aspect ratio and bar colour, so you decide the balance between file size and quality.