BlueMask

BlueMask is a local image-redaction tool. Secure masking replaces covered pixels before you share a photo or screenshot.

Use BlueMask offline

The offline edition packages the BlueMask editor into one HTML file. It can mask and export an image without contacting a processing server.

Download the offline edition ↓

Offline workflow

  1. Download the offline edition.
  2. Verify its SHA-256 hash against the published build manifest.
  3. Turn off Wi-Fi and mobile data and unplug Ethernet.
  4. Open the downloaded HTML file.
  5. Choose the image, apply secure masks, and review every covered region at 100%.
  6. Export and inspect the flattened PNG.
  7. Close BlueMask before reconnecting the device.

Your device controls its network connection. BlueMask cannot disconnect it for you.

Opening BlueMask.html directly from disk disables the offline-edition, source, manifest, and evidence downloads. Links to Bluethroat Labs and the research references remain in the file. They need a network connection, and masking does not use them. Privacy, Terms, and Support are separate pages, so those relative links are not available inside the single downloaded file.

What offline use proves

Successfully using the editor while disconnected demonstrates that masking and export do not require a server.

It does not prove that the BlueMask file, browser, extensions, operating system, or device is trustworthy. Review the published source and hashes when the sensitivity of the image warrants it.

The retained offline check opens this editor with browser network emulation disabled. It is not a physical radio-off test on a phone.

Current build

Build ID
d13b8b632e64
Release status
Release candidate · physical iPhone/Safari and Android/Chrome testing and production sign-off remain pending
Hosted homepage SHA-256
2e13f7032825deed6d622c790c7470257b29615f1487c125c335cec53cb96be3
Offline SHA-256
e28592ebcbe4af0e54a0e9c67759bd90489002cfe8649db925f0187eb7ead84c
Renderer SHA-256
5bb27f45846222924a8136f80717ea53578a02551628e7dade75e14a08dcb383
Source archive SHA-256
6dda8174ac8dc64410ca0a18366f9cb9b3db5373be6d3a94e9994e4404613bfd
Evidence archive SHA-256
11850585860e071292078d697678032de41315e00ff8e3ca24565ae5d3eba42e

Source: github.com/BluethroatLabs/bluemask — source available, not open source.

Build manifest: View the generated manifest and artifact hashes.

Accepted images: PNG, JPEG, or WebP, up to 35 MB (35 × 1024 × 1024 bytes), 24 megapixels, and 12,000 pixels on the longer side.

Keyboard editing: add a region, change its coordinates, undo, redo, and export from the controls. Dragging to draw, move, or resize uses a pointer.

Browser evidence: headless Chrome only. No retained Firefox or Safari desktop result. Phone results are emulated, not physical devices.