Web Watermark Tool

Precise watermarks by domain, URL, IP, or Cookie. Prevents mistakes on prod. Includes contrast color, border, activity fade.

【Why you need this】 Ever confused test.app.example.com with app.example.com? Or accessed an admin panel via VPN IP without any visual clue about which environment you're on? Web Watermark Tool overlays customized watermarks on web pages that match your rules, preventing catastrophic mis-operations on the wrong environment. 【Six rule types — covers real-world scenarios】 • Exact host — e.g. app.example.com • Host suffix — matches all subdomains of example.com • URL regex — path-based routing like /admin • Exact IP — VPN internal 192.0.2.5 • IP CIDR — entire subnets like 10.0.0.0/8 • Cookie — deploy=canary for canary rollouts 【Highlights】 • Smart contrast color — auto-inverts against page background using CSS mix-blend-mode • Immersive border — solid inset frame around the viewport catches your attention peripherally • Mouse fade — auto-dims watermark during heavy interaction, restores when idle • Toolbar badge — PROD / TEST short label on the icon, know your env without opening the page • Cross-iframe matching — each frame evaluates independently by its own URL • AI-assisted rule generation — one-click copy a prompt to ChatGPT / Claude and describe your setup in plain language 【Privacy】 All configurations are stored in your own Chrome account (chrome.storage.sync). No third-party servers. No data collection. No tracking. The "Copy AI Prompt" button only copies a built-in template to your clipboard — it does NOT include your rule data. 【For】 Frontend / full-stack developers, QA engineers, SRE, and anyone juggling multiple similar-looking web environments. 【Getting started】 Click the ? icon in the top-right for a quick guide. All configs support JSON import / export for team sharing and multi-device migration. Available in Simplified Chinese, Traditional Chinese, English, Japanese, and Spanish. 【Feedback】 Report bugs or suggest features at: https://github.com/jinnersun/web-watermark-prompt/issues