Hide what shouldn’t be shared
Screenshots are one of the most common ways sensitive information leaks: an email address in the corner, an auth token in a URL bar, a customer name in a table. This redactor lets you drag over those areas and bake the redaction directly into the image before you post it anywhere.
How it works
The original image is drawn onto a hidden backing canvas at its native resolution. When you drag a rectangle, the selected region is processed and written back into the backing canvas — the change is permanent, not a visual overlay:
- Black box fills the region with solid opaque black.
- Pixelate / blur divides the region into square blocks, averages the colour of each block, and repaints every pixel in that block with the average. Because the source pixels are overwritten, the detail cannot be recovered.
The on-screen canvas is a scaled copy for comfortable editing, but the export always comes from the full-resolution backing canvas, so quality is preserved.
Tips and notes
- Prefer a black box for the highest-sensitivity items like passwords, API keys, and account numbers — it removes all residual signal.
- Use a larger block size when pixelating small text; light mosaics over tiny fonts can occasionally be partially reconstructed.
- Undo rebuilds the image from a pristine copy and re-applies all but the last redaction, so it is always exact.
- Everything is local — safe for screenshots containing confidential or personal data.