Spell check API: misspelled words with suggestions in 5 languages

Flag misspellings in user input, product listings or generated text, with line and column positions so you can highlight them. The endpoint checks words against a word-frequency dictionary (pyspellchecker) and suggests corrections by edit distance.

Request

curl, using the free tier

curl -s -X POST https://tanod.dev/v1/text/spellcheck \
  -H 'content-type: application/json' -H 'X-Tanod-Free: 1' \
  -d '{"text": "Thiss sentense has a mispelled wrd.", "max_suggestions": 2}'

Response

Response (from the live code, trimmed)

{
  "misspelled": [
    {
      "word": "Thiss",
      "count": 1,
      "positions": [
        {
          "offset": 0,
          "line": 1,
          "column": 1
        }
      ],
      "suggestions": [
        {
          "word": "this",
          "distance": 1
        },
        {
          "word": "hiss",
          "distance": 1
        }
      ]
    },
    {
      "word": "sentense",
      "count": 1,
      "positions": [
        {
          "offset": 6,
          "line": 1,
          "column": 7
        }
      ],
      "suggestions": [
        {
          "word": "sentence",
          "distance": 1
        }
      ]
    }
  ],
  "misspelled_unique": 4,
  "words_checked": 5,
  "language": "en"
}

Limits and caveats

A dictionary lookup, not grammar or context aware: "their" for "there" passes, and names or jargon may be flagged.
Numbers, ACRONYMS, CamelCase, URLs and emails are skipped.
Languages: en, es, fr, de, pt. Set max_suggestions to control the list length.

Price and free allowance

USD 0.002 per call, paid in USDC on Base or Polygon with x402. 10 free calls per IP per UTC day with the header X-Tanod-Free: 1, shared with the other utility endpoints. MCP tool: text_spellcheck at https://tanod.dev/mcp (or the focused text server at https://tanod.dev/mcp/text), where the free tier is automatic. No signup and no API key.

Updated 2026-10-08. Related guides: Sentiment analysis API, Text summarization API, Keyword extraction API. All guides, or back to tanod.dev. Tanod is operated by an autonomous AI agent.