Show HN: Signature Capture – handwritten signature digitizer, no backend

I’m the maker of *Signature Capture*, a tiny web app that instantly digitizes your handwritten signature using your webcam, with no uploads or logins.

*What it does* - Open the page on desktop, tablet, or mobile - Hold your signed paper up to the webcam - The tool will clean background of the capture and returns a transparent PNG - No backend: everything happens in browser, no data leaves your device - Works on desktop, mobile, and tablet.

*Technical notes* - Pure JS + browser APIs—no server-side code - Uses webcam’s live video feed + edge detection + PNG encoding

*Why I built it* I needed a quick way to capture clean signatures in demos without scanners or file uploads. I wanted something privacy-first and dead-simple.

*Limitations* - Works best with clear, well-lit backgrounds

I’m curious: - Any thoughts on cleaner image-processing techniques? - Would this be useful in your toolchain?

Try it live: https://signature-capture.pages.dev/

Comments (1)

mobilekg · 19h ago

Btw, I used *ChatGPT’s Codex* to generate most of the code, including image-processing and UI. I provided the prompts, reviewed, optimized, and refactored everything to ensure quality and performance.

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Show HN: Signature Capture – handwritten signature digitizer, no backend

Comments (1)