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Silver Stone
Silver Stone

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Building privacy-first browser tools: QR, image metadata, and PDF editing without uploads

I have been expanding UsefulAtlas into a browser-local toolbox instead of adding hundreds of tiny utility pages.

The latest work includes:

QR Studio

Static QR generation
URL, text, Wi-Fi, vCard, email and SMS
Local image and camera decoding
Destination inspection before opening
PNG/SVG export

Image Toolbox

Resize / convert
EXIF and metadata inspection
GPS detection
Local metadata/privacy cleaning
Automatic re-inspection of cleaned output

PDF Toolbox

Merge / split / reorder
Text annotations
Pen and highlighting
Visual signatures
Undo / redo
Local PDF export

The main constraint has been simple:

Private files should stay in the browser when the task does not require a server.

That also creates some interesting engineering problems: PDF coordinate transforms, worker ownership, metadata container parsing, QR payload safety, Blob lifecycle cleanup, mobile input, and keeping heavy libraries lazy-loaded.

I am intentionally avoiding remote upload APIs for these workflows.

No MCP layer or agent API either - the human tool needs to be good first.

The project is live here:

https://usefulatlas.com/

If you build browser-local utilities too, I would be interested in what edge cases caused you the most trouble.

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