Privacy Architecture

Privacy Policy & Data Security

Last Updated: September 2026

1. The Core Privacy Guarantee: 100% In-Browser Processing

At Watermarker.online, privacy is not an afterthought or marketing phrase — it is fundamental to the software's architecture.We never upload your photos, illustrations, or graphics to our servers.

Every step of the watermarking lifecycle runs locally on your computing device via standard web browser APIs:

  • Image Decoding: Handled by your browser's native image decoders (via HTML5 Canvas and ImageBitmap).
  • Watermark Rendering: Drawn directly onto client-side canvas buffers utilizing CPU and GPU acceleration on your machine.
  • Batch Execution: Parallel Web Worker threads coordinate batch queues locally in background threads.
  • File Packaging: ZIP archives are compiled on-the-fly inside browser memory using client-side JavaScript (JSZip).

2. Do Your Images Ever Leave Your Device?

No. Your images are loaded into local memory (`blob:` and `canvas:` contexts) and stay within your browser sandbox. When you download your watermarked files or ZIP archive, the data is generated locally by your device.

3. What Information is Stored Locally?

Watermarker.online utilizes your browser's standard localStorage solely for convenience features:

  • Favorite Templates: A small array of template identifiers that you have marked with a star.
  • Custom Templates: Watermark configurations (text, fonts, colors, positions) that you explicitly click "Save Custom" on.
  • Export Preferences: Your recent choice of output format (JPEG, PNG, WebP) and filename suffix preference.

We do not store your images in persistent storage. As soon as you close or refresh the tab, any uploaded image files held in volatile memory are immediately discarded.

4. User Accounts and Telemetry

Watermarker.online does not require, support, or maintain user accounts, passwords, or emails. We do not track personal identifying information (PII) or sell data to third-party data brokers.

5. Original File Integrity

Your original uploaded files are strictly read-only within the browser session. Watermarker.online never overwrites or alters the source files on your computer's hard drive or mobile device storage.