ROI Video Encoder

Encode a region of interest at high bitrate and everything outside at a lower bitrate — see the file size savings in real time.

← Back to Concepts Video compression comparison
1

Select Video

Choose a local video file to work with.

Drop a video here, or click to browse
MP4, MOV, WebM, AVI — processed locally in your browser
2

Draw Region of Interest

Click and drag on the video to mark the area that should be encoded at high bitrate. Everything outside will use the lower bitrate.

Drag on the video to select your region of interest

Encoding Progress

1/2 Reference encode
0%
2/2 ROI encode
0%
Encoding runs in a browser WASM sandbox — speed depends on your machine and video length. A 30-second 1080p clip typically takes 1–3 minutes.
✓

Results

Reference file size
—
Full video at high bitrate
ROI-encoded size
—
Background at low bitrate
Actual savings
—
—
Region Reference ROI encode
ROI region — —
Background — —
Total — —
How it works: The background is blurred proportionally to the bitrate ratio before encoding, which reduces its spatial complexity. With CRF-based encoding, lower-complexity regions consume fewer bits — so the ROI retains full detail while the background uses far less of the bitrate budget. The weighted target bitrate is: roi_area × high_bitrate + bg_area × low_bitrate.