Free browser utility · local photo processing

Redact a photo with solid blocks

Cover selected areas with opaque black rectangles, then export a flattened PNG.

Choose a photo to begin

PNG, JPEG or WebP. Up to 25 MB, 24 megapixels and 10,000 pixels per side. Your original stays unchanged.

No photo selected.

Add a rectangle using original-image pixels

Choose a local PNG, JPEG or WebP to begin.

Cover every sensitive detail

Drag across the preview with a mouse, pen or finger to place a solid black rectangle. On a phone, scroll outside the image. Add a little margin around text and faces so no edges remain. There is no automatic detection: you choose every region.

Use coordinates for precise or keyboard editing

The coordinate controls use original-image pixels, with X and Y measured from the top-left corner. Enter a rectangle’s position, width and height, then add it. Undo removes the last block; clear removes all blocks. The source file remains unchanged.

Export, inspect, then share only the new copy

Generate the flattened PNG and inspect the downloaded file before sharing. The black pixels replace the covered pixels in that output; there are no editable redaction layers in the PNG. Do not share the original alongside it. Look for other identifying information, reflections, thumbnails held elsewhere, and details you may have missed.

Why solid blocks instead of blur

Blur and pixelation can leave enough visual structure to infer hidden information. This tool uses only opaque black fills. It cannot guarantee anonymity: context outside the blocks may still reveal a person, place or document.

Local processing, with clear limits

These are standalone website utilities, separate from the CalcLock iPhone vault. Selecting a photo does not import it into the app. The tool’s code processes selected images in your browser and does not upload them, use a remote image service or save them to browser storage. Downloaded files go wherever your browser normally saves downloads.

Re-encoding creates a new pixel-based copy without copying the original EXIF metadata. This applies only to the generated copy, not your original, backups or other shared copies. It is not a promise that every identifying detail has been removed: visible content can identify you, and browsers may add encoding information. Color rendering and orientation may differ between applications; inspect your output.

Inputs are limited to 25 MB, 24 million pixels and 10,000 pixels on either side. Some devices may run out of memory below these limits. Only browser-decodable PNG, JPEG and WebP files are accepted. Animated images are flattened to a browser-decoded frame; do not use this tool to preserve animation. Clear releases the tool’s image references and download URLs; it does not securely erase device memory or remove downloaded files.

More photo utilities

All planning and photo tools · Understand the vault’s privacy boundaries