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Getting Started with the GrammarBot API


Thanks for choosing the Grammar Bot API to integrate detection of grammar and spelling errors into your project. Using a new API can sometimes be a challenge, so we’ve written a quick 3-minute guide to walk you through how to make your first API call and interpret the results.

Update: Pre-Built Grammar Bot Clients

Let us know if you have a client to add to this list:

How it works

Grammar Bot is a simple API - just send us your text, then the API returns a list of potential grammar and spelling errors that we find. Please note that only English is supported at the moment (en-US or en-GB).

Step 1: Get an API Key

Receive your API Key instantly for free by entering your email address in this form.

Step 2: Make an API Call

Substitute 'XYZ123' in the API calls below with your API Key received in Step 1.  We recommend using cURL to make your first API call.

cURL Usage:

curl -X POST \
  -d "api_key=XYZ" \
  -d "language=en-US" \
  -d "text=I can't remember how to go their" \

Sample URL:

NOTE: While you may paste a "test URL" like the one above in your browser, Ajax requests will not work due to CORS restrictions.

You will then see a JSON response similar to the following output.

Sample Response:

  "software": {

    "name": "GrammarBot",
    "version": "4.3-SNAPSHOT",
    "apiVersion": 1,
    "premium": false,
    "premiumHint": "You might be missing errors only the Premium version can find. Upgrade to see what you're missing.",
    "status": ""
  "warnings": {
    "incompleteResults": false
  "language": {
    "name": "English",
    "code": "en-US",
    "detectedLanguage": {
      "name": "English (US)",
      "code": "en-US"
  "matches": [
      "message": "Statistics suggests that 'there' (as in 'Is there an answer?') might be the correct word here, not 'their' (as in 'It’s not their fault.'). Please check.",
      "shortMessage": "",
      "replacements": [
          "value": "there"
      "offset": 27,
      "length": 5,
      "context": {
        "text": "I can't remember how to go their.",
        "offset": 27,
        "length": 5
      "sentence": "I can't remember how to go their.",
      "type": {
        "typeName": "Other"
      "rule": {
        "id": "CONFUSION_RULE",
        "description": "Statistically detect wrong use of words that are easily confused",
        "issueType": "non-conformance",
        "category": {
          "id": "TYPOS",
          "name": "Possible Typo"

It's really that simple!  Ready to signup for your free API Key?


Take your learning a step further with these tutorials to help you get up and running quickly:

Request Limits

Grammar Bot offers the most generous free limits on grammar and spelling check, but it's not unlimited.  With an API key, you can receive 200 requests/day (~6000/mo) at no cost.  Without an API key, requests are limited to 50 per day per IP address (~1500/mo).  Contact us for paid options if you need higher volumes.

Document Length Limits

Text longer than 50,000 characters are not allowed.  Contact us if your application requires more than this.

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