Grammar Check API

POST

Fix spelling and grammar errors before user submissions get saved.

Grammar Check inspects text for spelling and grammar errors, returning the corrected wording, error count, and a modified flag. Paid plans add detailed rule descriptions, character offsets, and suggestions for every detected mistake.

Try it — live request, no key required

Request
POSTapi.apiverve.com/v1/grammarcheck
Body
Verification
Format

No key required to try it. Get a key to use it in your app.

Example
{
  "status": "ok",
  "error": null,
  "data": {
    "modified": true,
    "corrected": "The pig snorted when I saw it on the barn gate. I was a little mad because it woke up my puppy",
    "errorCount": 3,
    "corrections": [
      {
        "rule": "repeated_word",
        "message": "Did you mean to repeat the word \"The\"?",
        "position": {
          "start": 0,
          "end": 7
        },
        "suggestions": [
          "The"
        ]
      },
      {
        "rule": "spelling",
        "message": "Did you mean \"because\"?",
        "position": {
          "start": 67,
          "end": 74
        },
        "suggestions": [
          "because"
        ]
      },
      {
        "rule": "spelling",
        "message": "Did you mean \"puppy\"?",
        "position": {
          "start": 92,
          "end": 101
        },
        "suggestions": [
          "puppy"
        ]
      }
    ]
  }
}

About the Grammar Check API

Pass any raw string in the request body to scan it for grammatical issues and misspelled words. The response states whether modifications were needed, counts the total issues found, and provides the fully revised text. Subscribers on paid plans also receive character offsets, violated rules, and specific replacement suggestions for each error.

What people use it for

Content Management Proofing
Flag grammar mistakes in submitted blog drafts and substitute corrected sentences before publishing articles to readers.
Customer Support Messaging
When agents write replies in ticketing desks, the system uses the error count to warn them of uncorrected typos.
Resume Intake Screening
Job portals scan cover letters during applicant uploads, noting whether the text was modified to preserve clean candidate profiles.
Student Essay Feedback
Learning management platforms pass student submissions to display the number of errors and return properly formatted text.

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

Other ways to use Grammar Check

Same data, same APIVerve account, same credit balance — one key works on all of them.

Questions.

Common questions about the Grammar Check API.

Read the docs →
Is it cheap enough to check grammar on every user submission?
Yes. Each check costs 20 credits, which works out to about $0.003 per call on the Starter plan, or $3.00 per 1,000 calls. The Free plan gives you 10 checks each month to test your integration, while Starter covers 10,000 monthly checks.
Do I get error explanations and replacement suggestions on the Free plan?
No, detailed correction breakdown requires a paid plan. On the Free plan, you receive the corrected text, the error count, and a flag indicating if changes were made. Paid plans unlock the corrections list with violated rules, error positions, and specific replacement suggestions.
What types of writing mistakes does it detect?
It analyzes text for both grammatical mistakes and spelling errors. The response indicates whether any issues were found, reports the total error count, and provides a clean version of the text with all corrections applied.
What does the response look like if text contains no errors?
If your input text is already error-free, the modified flag returns false and errorCount is set to zero. The corrected text field simply returns your original submission without any alterations.
Can I highlight specific mistakes in an editor instead of auto-correcting?
Yes, on any paid plan. The premium corrections array provides character start and end positions alongside violated rules and suggested fixes. You can use those exact coordinates to build inline squiggly underlines and suggestion tooltips in your interface.

Ready to build with Grammar Check? Start with 200 free credits — one key unlocks all 300+ APIs.

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