nibbo
Pro $2

Compress MKV video

Reduce the size of MKV videos in your browser. Pick a size in MB and Nibbo keeps the picture sharp; the file never leaves your device.

Where is it going?
1 MB100 MB

Choose a video and Nibbo picks the size

Your file never leaves this device

MKV

MKV files come from OBS, screen recorders and downloads, and can hold almost any codec.

Browsers cannot open MKV themselves, so Nibbo uses FFmpeg compiled to WebAssembly. It is slower than the GPU path but still runs on your device.

How it works

  1. We read your video locally and measure how detailed (SI) and how much in motion (TI) it is.
  2. From the size you pick we compute an exact bitrate budget, then choose the resolution and frame rate that look best at that budget. Lower resolution with enough bits beats blocky full resolution.
  3. Your GPU encodes it through WebCodecs. Formats the browser cannot decode go through FFmpeg compiled to WebAssembly.
  4. If the result is even slightly over the limit, we re-encode with a corrected bitrate, so the file fits.

Questions

Are subtitles and extra audio tracks kept?

The first video and audio track are kept. Subtitle tracks and extra languages are dropped, so burn subtitles in first if you need them.

Is my video uploaded?

No. Nibbo runs in your browser and compresses the video on your device. You can switch off Wi-Fi after the page loads and it still works.

Why does my video get a lower resolution?

A small file has a fixed number of bits. Spreading them over fewer pixels gives a clean picture; keeping full resolution would make it blocky.