Profanity filter: find and censor swear words

Paste English text to see which swear words it contains, where they are, and a censored copy. It catches common disguises like f.u.c.k, sh1t and fuuuck (see limitations). This is a word filter based on a word list, not AI moderation, and it supports English only.

Your text is sent to this site's API, checked in memory, and discarded. It is never stored or logged (privacy).

Use the API

curl -s https://profanity-api.mike-tusa.workers.dev/v1/check \
  -H 'content-type: application/json' \
  -d '{"text":"well f.u.c.k that sh1t","censor":true}'

Get a free key (1,000 requests/day, commercial use OK): curl -s -X POST https://profanity-api.mike-tusa.workers.dev/v1/keys -H 'content-type: application/json' -d '{}'. Full reference: API docs.

Limitations

• English only. It's a word list, so it doesn't judge context, intent or tone, and it can miss new slang.
• Not caught: letters split across lines, spaced letters followed by a word (f u c king), most symbol-masked spellings (f**k, b*tch, s**t), phonetic spellings (phuck), deliberate misspellings and words outside the list. Standalone fu/FU is not flagged on purpose (kung fu, Fu Manchu); masked forms like fu*k, fu**ing and fu.ck are, but not fu ck (space), doubled separators (fu..ck, fu--ck) or a hidden character between fu and the mask (e.g. a zero-width space in fu*k).
• Caught: leetspeak (sh1t, $h!t), look-alike and accented letters (fück, ｆｕｃｋ), repeated letters (fuuuck), dotted/spaced letters (f.u.c.k, s h i t), dotted letters with a suffix (f.u.c.king, s.h.i.tty), and hidden characters (soft hyphens, zero-width and direction-control characters, other invisible format characters, combining and enclosing marks).
• It can flag innocent words that contain a swear word. We whitelist the common ones (like Scunthorpe, cockpit, shiitake, Shiite, cumin, Fukushima, Dickinson). Known false positives: the first name Dick and the place/surname Cumming (e.g. Cumming, Georgia) are still flagged; add "dick" or "cum" to allow if your text has them. Note that allow: ["cum"] turns off all detection of that word (including its slang use), so only use it if place/surname text matters more to you. Rare edge cases also flagged: Fu-kien (old spelling of Fujian) and fu.kr-style domains. Use allow for any others.

Pricing

Paid tier prices are estimates and not available to buy yet. Per-request allow/deny lists (up to 50 words each) work on every tier, including free.

Questions or abuse reports: mike.tusa@gmail.com.