Mosaic / Redact
Mosaic & redaction tool: drag one or more rectangles onto an image, choose pixel mosaic or Gaussian blur with adjustable block size; supports undo and clear. Commonly used to redact IDs, license plates, and chat screenshots. In-browser, zero upload.
How to use
Purpose
Add mosaic / pixelation / blur over sensitive regions of an image — rectangular, circular, or freehand brush selection with adjustable pixel size and blur strength. Critical for privacy: hiding ID numbers, phone numbers, faces, license plates, credit card digits in screenshots before sharing publicly. Strictly local processing — uploading sensitive images defeats the entire point.
Steps
- Upload the image needing redaction
- Pick a tool: rectangle, ellipse, or freehand brush
- Set mosaic pixel size (5-50px) or blur radius
- Drag or paint over the regions to obscure
- Stack multiple redaction regions
- Export JPG / PNG once verified
FAQ
- Can mosaic be reversed?
- Mosaic with sufficient pixel size (>20px) is generally irreversible. However, with prior knowledge of the content and repeated application to similar data, AI inversion is theoretically possible. For critical numbers (ID, credit card), use a solid black bar — irreversible and definitive.
- Is the image uploaded?
- Never. Redaction's entire purpose is privacy protection — uploading to a server contradicts the goal. We process strictly locally.
- Can I redact video frames?
- This tool handles still images. For video, you'd need a video editor or per-frame screenshot + composite.
- Mosaic vs Gaussian blur?
- Mosaic = blocky pixel averaging (looks like grid). Blur = smooth diffusion (looks like fog). Mosaic better hides characters; blur better softens backgrounds / faces naturally.
- Can I redact specific digits but keep name?
- Yes — freehand brush gives pixel-precise control; redact just the ID number digits while leaving the name visible.
Use cases
- Chat screenshots — redact names, phone numbers
- ID photos — partial number masking
- Credit / debit card middle digits
- Family / kid photos — face privacy
- Job application / resume sharing — contact privacy
Use cases
Chat names, ID numbers, credit cards, faces, license plates — local-only redaction is privacy-critical. For irreversible mask, use solid black instead of mosaic.