Spell Checker API

About the Spell Checker API

A spell check API you can call to check spelling and correct text: send English text and get back whether it passes, how many distinct misspellings were found, and suggested corrections for each misspelled word. Turn on autocorrect to get correctedText, the text with each misspelling replaced by its first suggestion. Paid plans add total and per-word occurrence counts, and offsets to get the start and end position of every occurrence for highlighting in an editor. Spell Checker works by checking each word of the text against an English dictionary and suggesting likely replacements for the ones it does not recognise.

What people use it for

Rich Text Editors

Flag typos in user-submitted drafts in real time and display replacement suggestions directly inside the editing interface.

Customer Support Chat

Before sending agent replies to customers, scan message drafts to detect misspelled words and prevent communication errors.

Form Submission Sanitization

Job boards inspect candidate resumes and cover letters upon upload to tally spelling mistakes before forwarding applications to recruiters.

Student Essay Assessment

To automate rubric scoring, learning platforms scan student papers to count uncorrected typos and show teachers the identified errors.

Ways to call it

One endpoint, many ways in — REST with JSON, XML, YAML and CSV, plus GraphQL and an MCP interface for AI agents.

JSON

Default REST response

XML

Markup format

YAML

Human-readable

CSV

Tabular export

Beta

GraphQL

Query language

New

MCP

For AI agents

Request parameters — POST /v1/spellchecker

Sent as JSON in the request body. Premium parameters are accepted on every plan but only take effect on plans that include them. Anything not listed here is dropped rather than passed through.

Required

Optional

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curl -X POST "https://api.apiverve.com/v1/spellchecker" \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"text":"I neeed to call my friend on telephine today!","autocorrect":true,"offsets":true}'

Authentication

Send your key in the x-api-key header. That is the only auth step — no token exchange, and no per-endpoint scope to configure.

Response — POST /v1/spellchecker

Every APIVerve endpoint returns the same three top-level keys, so one response handler covers your whole integration: status, error and data. Only data changes shape.

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{
  "status": "ok",
  "error": null,
  "data": {
    "spellPass": false,
    "mispellingsFound": 2,
    "totalOccurrences": 2,
    "corrections": [
      {
        "word": "neeed",
        "suggestions": [
          "needed",
          "need",
          "needy",
          "Neel",
          "needs"
        ],
        "occurrences": 1,
        "offsets": [
          {
            "start": 2,
            "end": 7
          }
        ]
      },
      {
        "word": "telephine",
        "suggestions": [
          "telephone",
          "telephoned",
          "telephoner",
          "telephones",
          "telephony"
        ],
        "occurrences": 1,
        "offsets": [
          {
            "start": 29,
            "end": 38
          }
        ]
      }
    ],
    "correctedText": "I needed to call my friend on telephone today!"
  }
}

Response fields

Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.

Response headers

Every response carries your balance, so your own code always knows where it stands without polling anything. All four are exposed to browsers through CORS.

Errors

Read the HTTP status first, then error for the specific reason. The body names the parameter that has to change.

What a call costs — 10 credits per call

Credits are shared across every APIVerve API — one balance, one key, one bill. Failed requests never count against it, so a rejected input costs nothing.

Calls are what the credits buy at this API's rate — spend them here, on any of the other APIs, or across both. Nothing is reserved per endpoint.

Zero-code embed — one snippet, no backend

Drop an interactive Spell Checker form onto any page. The widget calls the API for you, so no key ever appears in your markup and there is nothing to deploy.

Changelog — Spell Checker API

Every change to this endpoint, newest first. Breaking changes ship as a new version and the previous one keeps serving — response fields are added, never removed or retyped in place, so an integration written against v1 keeps working.

Currently v1