AI text cleaner
Paste AI output, tick what to fix and get plain, clean text: hidden characters, Markdown, curly quotes, em dashes, bullet symbols, double spaces and blank lines. Every fix is optional and shown in a diff.
Nothing is sent to a server: the text stays in your browser, the tool runs offline once the page is loaded. Ctrl+Enter runs it.
- Runs the hidden character scan (zero-width, spaces, soft hyphens, bidi, controls, lookalikes) and counts each category
- Strips Markdown: headings, bold and italics, links, images, lists, tables, code fences, block quotes, horizontal rules
- Em dashes become a comma by default; other choices are spaced hyphen, space, period or keep
- Smart quotes, ellipsis, emoji and HTML tags are off by default so the text keeps your typography unless you ask
- Whitespace: double spaces, trailing spaces and runs of blank lines are collapsed
What AI text needs cleaned
Text copied from ChatGPT, Claude, Gemini or Copilot arrives with three kinds of debris. Formatting: Markdown headings, asterisks, bullet syntax and tables that were rendered in the chat window but become raw symbols in a plain-text field. Typography: curly quotes, em dashes and ellipsis characters that some destinations turn into question marks and that some readers now associate with machine writing. Invisible characters: zero-width spaces, narrow no-break spaces and, less often, soft hyphens or bidi marks that break searches and matches. This tool handles the three in one pass, and shows what it changed.
The twelve fixes
| Fix | What it does | Default |
|---|---|---|
| Hidden characters | Same engine as the invisible character remover: zero-width, exotic spaces, soft hyphens, bidi controls, controls, variation selectors, lookalike letters | On |
| Markdown | Headings, bold, italics, strike, inline code, code fences, links, images, lists, tables, block quotes, rules. Same engine as the Markdown remover | On |
| Links become | Text only, or text (URL) when you need to keep the address | Text |
| Smart quotes | Curly double and single quotes and apostrophes to straight ones (see smart quotes to straight quotes) | Off |
| Em dashes | Comma, spaced hyphen, space, period, or keep; double hyphens are treated the same way | Comma |
| Ellipsis | The single character U+2026 to three dots | Off |
| Bullet symbols | • ◦ ▪ – at the start of a line to a hyphen | On |
| Emoji | Removed, along with the space before them | Off |
| HTML tags | Tags stripped, entities decoded | Off |
| Double spaces | Runs of spaces to one | On |
| Trailing spaces | Spaces at line end removed | On |
| Blank lines | Three or more line breaks to two | On |
How to use it
- Paste the text or click Try with a sample.
- Untick anything you want to keep. Curly quotes and emoji are kept unless you ask, because many people want them.
- Click Clean. The result shows counters (hidden characters found, Markdown marks removed, dashes replaced, lines changed), a diff and a highlighted view of the hidden characters.
- Copy, download as .txt, or copy a link that stores your settings.
What this cleaner is not
A clean text is not an unmarked text. Anthropic marks Claude output with a statistical watermark in the choice of words, and Google's SynthID-Text does the same for Gemini; neither leaves any character to remove. Cleaning invisible characters from ChatGPT text removes a real, visible artefact and nothing more. If your question is the watermark, the AI text watermark remover hub explains what each mark is and which tool applies; the ChatGPT watermark remover page covers the ChatGPT case specifically.
One job at a time
Each fix also exists as its own page when you only need one: em dash remover with eight replacement modes, invisible character remover with per-category control, Markdown remover, smart quotes converter. To count writing habits rather than clean them, see the AI words checker; to look at each character, the Unicode inspector.
Privacy
The cleaner runs in your browser. Your text is not sent to unmarker.io or anyone else, is not stored and is not logged; only the button click is counted anonymously.
Unmarker is an independent product, not affiliated with or endorsed by Anthropic.
Questions people ask
Does the AI text cleaner remove the AI watermark?
No. It removes visible and invisible characters and formatting. Claude's and Gemini's watermarks are statistical, in the choice of words, and survive any character clean-up. Use the watermark tools for that.
Which hidden characters does it find?
Zero-width space, zero-width joiner and non-joiner, word joiner, byte order mark, soft hyphen, bidi controls, C0 and C1 controls, variation selectors, tag characters, no-break and exotic spaces, and Cyrillic or Greek letters inside Latin words. Each is counted and highlighted.
Can I keep the Markdown?
Yes, untick Markdown. You can also keep links as text (URL) so nothing is lost when a link is turned to plain text.
Why are smart quotes off by default?
Because curly quotes are correct typography in most publishing contexts. Turn the option on when the destination needs straight quotes, such as code, JSON, CSV or a form that rejects them.
Is there a size limit?
The tool handles book-chapter sized texts in under a second on a phone. Very long texts still work; only the diff view is skipped past about 250,000 line pairs to keep the page responsive.
Is anything uploaded?
No. The script runs in your browser and works offline once the page has loaded.