I Hate Watermarks

Paste AI-generated text, see the invisible characters hidden in it, and copy a clean version. The cleaner runs entirely in the browser, so pasted text never leaves the page. The site is a static export and uses Google Analytics to measure page visits.

It removes invisible-character watermarks: zero-width spaces and joiners, BOMs, soft hyphens, bidi overrides, variation selectors, Unicode tag characters (which can spell out hidden messages), private-use/noncharacter/reserved code points and exotic spaces. It keeps the invisible characters real text needs (emoji ZWJ sequences, Persian/Indic joiners, flag tag sequences, RTL marks).

It cannot remove statistical watermarks such as SynthID-Text, which live in word choice rather than in any character.

Agent skill

skills/remove-ai-watermarks is an Agent Skill that gives coding agents the same cleaner. Install it with the skills CLI, which supports Claude Code, Codex, Cursor, Gemini CLI, GitHub Copilot and more:

npx skills add heyyarun/i-hate-watermarks

Or copy the folder by hand into ~/.claude/skills/ (Claude Code) or ~/.agents/skills/ (Codex). Then ask your agent something like "check essay.md for hidden AI watermark characters and clean it". The skill runs scripts/watermarks.mjs, a single file with no dependencies that needs Node.js 18 or newer:

node skills/remove-ai-watermarks/scripts/watermarks.mjs inspect essay.md
node skills/remove-ai-watermarks/scripts/watermarks.mjs clean -i essay.md
pbpaste | node skills/remove-ai-watermarks/scripts/watermarks.mjs clean | pbcopy

watermarks.mjs is generated from packages/skill and committed so the skill folder works on its own. After changing packages/core or packages/skill, rebuild it with corepack pnpm build:skill; a test fails if the committed file is out of date.

Layout

• packages/core: the cleaning engine (TypeScript, no dependencies). Port of watermarks-remover's Layer A engine.
• packages/skill: the skill's command-line front end, bundled into skills/remove-ai-watermarks/scripts/watermarks.mjs.
• skills/remove-ai-watermarks: the installable skill (SKILL.md plus the bundled script).
• apps/web: the Next.js site (output: "export").

Develop

Uses pnpm through corepack (bundled with Node), so pnpm does not need to be on your PATH. If it is, plain pnpm <script> works too.

corepack pnpm install
corepack pnpm dev          # http://localhost:3000
corepack pnpm test         # engine and skill tests, incl. parity with the Python original
corepack pnpm typecheck    # works from a clean checkout; generates Next route types first
corepack pnpm build        # static site in apps/web/out
corepack pnpm build:skill  # skills/remove-ai-watermarks/scripts/watermarks.mjs

Regenerating data

Both scripts need uv. Fixtures also need a checkout of the reference repo.

cd packages/core
corepack pnpm gen:names                                   # src/unicode-names.generated.ts
corepack pnpm gen:fixtures /path/to/watermarks-remover    # test/fixtures/parity.json

License

MIT. See LICENSE and NOTICE.