v1Operational

HumanizeIt API

Make any text undetectable. Programmatically.

Get API Key Try the playground

Quick Start

Get your API key

Create a key in the dashboard. It's shown only once — save it securely.

Make a request

Send text to analyze or humanize via a simple POST request.

Get results back

Receive human-sounding text or an AI detection score as JSON.

curl

curl -X POST https://humanizeit.app/api/v1/analyze \
  -H "Authorization: Bearer sk_live_your_key_here" \
  -H "Content-Type: application/json" \
  -d '{"text": "The mitochondria is the powerhouse of the cell."}'

response

{
  "score": 72,
  "confidenceBand": "likely-ai",
  "patterns": [...],
  "stats": { "avgSentenceLength": 8, "vocabularyRichness": 0.85, ... },
  "wordCount": 8
}

Authentication

All API requests require a Bearer token in the Authorization header. Keys are generated in your dashboard and shown only once at creation.

http

Authorization: Bearer sk_live_aBcDeFgHiJkLmNoPqRsT...

Security: Never expose API keys in client-side code, public repositories, or browser requests. Always use keys server-side.

Endpoints

POST/api/v1/analyze

Analyze text for AI-generated patterns and return a detection score.

Request Body

Field	Type	Required	Description
text	string	Yes	The text to analyze (10–10,000 chars)

Request

curl

curl -X POST https://humanizeit.app/api/v1/analyze \
  -H "Authorization: Bearer sk_live_..." \
  -H "Content-Type: application/json" \
  -d '{"text": "Your text to analyze..."}'

JavaScript

javascript

const res = await fetch("https://humanizeit.app/api/v1/analyze", {
  method: "POST",
  headers: {
    "Authorization": "Bearer sk_live_...",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({ text: "Your text to analyze..." }),
});
const data = await res.json();

Response

json

{
  "score": 72,
  "confidenceBand": "likely-ai",
  "patterns": [
    { "name": "uniformSentenceLength", "score": 0.8, "weight": 1.5 },
    { "name": "repetitiveTransitions", "score": 0.6, "weight": 1.2 }
  ],
  "stats": {
    "avgSentenceLength": 18.5,
    "vocabularyRichness": 0.72,
    "sentenceCount": 12
  },
  "wordCount": 222
}

Response Schema

Field	Type	Description
score	number	AI detection score 0–100 (higher = more likely AI)
confidenceBand	string	human / mixed / likely-ai / ai-generated
patterns	array	Detected AI patterns with scores and weights
stats	object	Text statistics (sentence length, vocabulary, etc.)
wordCount	number	Word count of the input text

POST/api/v1/humanize

Rewrite text to sound more natural and human-written.

Request Body

Field	Type	Required	Description
text	string	Yes	The text to humanize (10–10,000 chars)
tone	string	No	Tone of the output (default: standard)
intensity	string	No	How aggressively to rewrite (default: medium)
passes	number	No	Number of humanization passes, 1–3 (default: 1). Higher passes auto-escalate intensity to reduce AI score below 45%.

Tone Options

Value	Description
standard	Natural, balanced rewriting
formal	Professional, polished tone
casual	Conversational, relaxed style
academic	Scholarly, structured language
storytelling	Narrative, engaging voice
professional	Business-appropriate communication

Intensity Options

Value	Description
light	Minimal changes — preserves most of the original structure
medium	Balanced rewriting — natural-sounding with moderate changes
heavy	Aggressive rewriting — maximizes undetectability

Request

curl

curl -X POST https://humanizeit.app/api/v1/humanize \
  -H "Authorization: Bearer sk_live_..." \
  -H "Content-Type: application/json" \
  -d '{"text": "Your text...", "tone": "casual", "intensity": "medium", "passes": 2}'

Response

json

{
  "humanizedText": "So here's the thing about mitochondria, they're basically the engine room of every cell...",
  "originalScore": 78,
  "humanizedScore": 18,
  "scoreDelta": 60,
  "confidenceBand": "low",
  "tokensUsed": 312,
  "passes_run": 2,
  "score_history": [78, 51, 18]
}

GET/api/v1/usage

Check your current API usage and quota.

curl

curl https://humanizeit.app/api/v1/usage \
  -H "Authorization: Bearer sk_live_..."

Response

json

{
  "plan": "PRO",
  "wordsUsed": 12450,
  "wordsLimit": 50000,
  "apiRequestsUsed": 247,
  "apiRequestsLimit": 1000,
  "monthlyResetAt": "2026-04-01T00:00:00.000Z"
}

Rate Limits

API requests are rate-limited per billing cycle. Every response includes rate limit headers.

Plan	Requests/month	Keys allowed	Max text length
FREE	0 (no API access)	0	5,000 chars
PRO	1,000	3	10,000 chars
TEAM	10,000	10	10,000 chars

Rate Limit Headers

Header	Description
X-RateLimit-Limit	Total requests allowed this period
X-RateLimit-Remaining	Requests remaining
X-RateLimit-Reset	Unix timestamp of next reset
Retry-After	Seconds until you can retry (on 429 only)

429 Response

json

{
  "error": {
    "code": "QUOTA_EXCEEDED",
    "message": "Monthly API request quota exceeded."
  }
}

Error Codes

Code	HTTP	Description	Solution
UNAUTHORIZED	401	Invalid or missing API key	Check your Authorization header
TEXT_TOO_SHORT	400	Text under 10 characters	Provide longer text
TEXT_TOO_LONG	400	Text over 10,000 characters	Shorten your text
QUOTA_EXCEEDED	429	Monthly quota reached	Wait for reset or upgrade plan
INVALID_JSON	400	Request body is not valid JSON	Check your JSON formatting
INTERNAL_ERROR	500	Server-side error	Retry or contact support

Playground

Test the API directly from your browser. Enter your API key and try a request.

API Key

Not stored — only used in-memory for this request

Endpoint

Text

Response

Response will appear here

cURL command

curl -X POST /api/v1/analyze \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"text":"Your text here..."}'

Changelog

v1.0March 2026

Initial release. Two endpoints: analyze and humanize. Rate limiting, hash-based API key authentication, and interactive playground.