Mosaic and image redaction guide

Step by step

1. Choose images and select a preview. Drag on the image to create a rectangle; drag a selected rectangle to move it. Add up to 20 regions.
2. Use Add region for keyboard editing, select a region, and enter its left/top and width/height percentages. Remove a region or clear all to start over.
3. Choose Pixelate and set a block size from 4 to 100 px, or choose Solid cover and an opaque color. Inspect every image using the preview selector.
4. Apply mosaic and inspect the exported results. Download individual files or a ZIP, save a preset, or continue to another tool. Keep the original separately.

Relative regions across a batch

Regions are percentages of each image. A rectangle at left/top 25%, width/height 50% covers the same relative area on different dimensions. This is useful for consistent screenshot layouts, but it does not track faces or text. Images with different layouts need separate batches or adjusted settings. The saved preset includes these rectangles, mode, block size, color and export settings.

Use solid cover for sensitive details

Pixelation changes visible detail but may leave words or faces recognizable. For sensitive information, choose an opaque solid cover and ensure it fully covers the content on every exported image. There is no automatic face detection. The exported cover is merged into the pixels, not saved as a removable layer. Inputs are limited to 50 MB and 40 MP per image, output to 8192 px per side and 16 MP.

Questions and answers