Profanity Filter API

Detect and censor profanity and offensive words in user-generated text. Supports 25+ languages (English, Spanish, French, German, Italian, Portuguese, Dutch, Russian, Japanese and more), leetspeak (sh1t, @ss), custom blocked words and an allow-list for false positives.

Authentication & base URL

Subscribe through one of our marketplace listings; your marketplace API key and base URL are shown there. All endpoints return JSON over HTTPS, served from a global edge network (typically 20–150 ms).

Subscribe on RapidAPI

Endpoints

GET `/v1/profanity`

Check and censor text

Parameter	In	Description	Example
`text` *	query	Text to check (or POST it as the body)	`What the f*** is this sh1t`
`lang`	query	Comma-separated language codes (en, es, fr, de, it, pt, nl, ru, ja...)	`en`
`fill`	query	Character used to censor	`*`
`add`	query	Extra words to block, comma-separated
`allow`	query	Words to never flag, comma-separated
`leet`	query	Detect leetspeak (true/false)	`true`

POST `/v1/profanity`

Check and censor text (POST text body)

Request body: text/plain

Parameter	In	Description	Example
`lang`	query	Comma-separated language codes (en, es, fr, de, it, pt, nl, ru, ja...)	`en`
`fill`	query	Character used to censor	`*`
`add`	query	Extra words to block, comma-separated
`allow`	query	Words to never flag, comma-separated
`leet`	query	Detect leetspeak (true/false)	`true`

Example

GET /v1/profanity?text=What+the+f%2A%2A%2A+is+this+sh1t&lang=en&fill=%2A&add=&allow=&leet=true

{
  "isProfane": true,
  "count": 1,
  "matches": [
    {
      "word": "sh1t",
      "index": 22
    }
  ],
  "censored": "What the f*** is this ****",
  "languages": [
    "en"
  ],
  "attribution": "Word lists: List of Dirty, Naughty, Obscene, and Otherwise Bad Words (Shutterstock), CC BY 4.0"
}

Use cases

Chat and comment moderation, usernames and nicknames validation, game lobbies, review sites, kids' apps, pre-filtering text before publishing or sending to an LLM.

Why this API

Fast: global edge network, answers in milliseconds.
Returns isProfane, every match with its position and a censored copy of the text.
Whole-word matching (no Scunthorpe problem) with accent folding.
Word lists: List of Dirty, Naughty, Obscene, and Otherwise Bad Words (Shutterstock), CC BY 4.0.
Fair pricing: Free plan 500 requests/month, Pro 25,000 for $4.99, Ultra 150,000 for $14.99.

Support

Questions or a feature you need? Open a thread in the Discussions tab.

Pricing

Free plan with 500 calls per month, then Pro (25,000 calls for $4.99/month) and Ultra (150,000 calls for $14.99/month). See all plans.