Remove Watermark Without Uploading: How We Built an In-Browser AI Editor

Description and use

ClearPix performs watermark removal entirely in the browser by downloading ONNX models once, caching them in IndexedDB, and running inference on WebGPU (with WASM fallback), ensuring user media never leaves the device.

Problem

Users are uncomfortable uploading sensitive photos to online watermark removers that process images on remote servers, raising privacy concerns.

Outcome

ClearPix achieves privacy‑first watermark removal by moving all inference to the client, reducing first‑visit latency through prefetching, and ensuring structural privacy via client‑side caching and no‑upload guarantees.

Workflow

• Open ClearPix tool page
• Browser downloads ONNX model weights from R2 CDN (with mirrors and fallback)
• Model weights are cached in IndexedDB for future use
• ONNX Runtime Web creates a session preferring WebGPU, falling back to WASM if needed
• User uploads image/video locally
• Image/video is decoded, processed, and re-encoded entirely in the browser
• Result is displayed to the user
• Optional aggregate analytics events are sent (no media data)

Evidence

Your image goes up, gets processed on someone else's GPU, and comes back down. Whether the privacy policy says the file is deleted afterward, you have no way to verify it, and neither do we.

Source

When you open a tool page, your browser downloads ONNX model weights (once, then cached forever), loads them into ONNX Runtime Web, and runs inference on WebGPU where available with a WASM fallback.

Source