Text Similarity API Reference

Overview

Text Similarity works by comparing the two texts and calculating the similarity score based on various factors. It returns the similarity score in a structured format.

Endpoint

One host, one path per API. The block below shows this call in four languages; every one of them is the same HTTP request. Making requests covers the timeouts, retries and parameter rules that apply to all of them. The SDKs wrap the same call in a typed client.

POSThttps://api.apiverve.com/v1/textsimilarity

curl -X POST https://api.apiverve.com/v1/textsimilarity \
  -H "x-api-key: your_api_key_here" \
  -H "Content-Type: application/json" \
  -d '{
  "text1": "I'm so excited that tomorrow is going to be sunny! Can't wait!",
  "text2": "We're pretty excited about the weather tomorrow. It's going to be sunny!"
}'

const res = await fetch('https://api.apiverve.com/v1/textsimilarity', {
  method: 'POST',
  headers: {
    'x-api-key': 'your_api_key_here',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
  "text1": "I'm so excited that tomorrow is going to be sunny! Can't wait!",
  "text2": "We're pretty excited about the weather tomorrow. It's going to be sunny!"
}),
});

if (!res.ok) throw new Error(`${res.status} ${await res.text()}`);

const { data } = await res.json();
console.log(data);

import requests

res = requests.post(
    "https://api.apiverve.com/v1/textsimilarity",
    headers={"x-api-key": "your_api_key_here"},
    json={
    "text1": "I'm so excited that tomorrow is going to be sunny! Can't wait!",
    "text2": "We're pretty excited about the weather tomorrow. It's going to be sunny!"
},
    timeout=15,
)
res.raise_for_status()

print(res.json()["data"])

package main

import (
	"fmt"
	"io"
	"net/http"
	"strings"
)

func main() {
	body := strings.NewReader(`{
  "text1": "I'm so excited that tomorrow is going to be sunny! Can't wait!",
  "text2": "We're pretty excited about the weather tomorrow. It's going to be sunny!"
}`)
	req, _ := http.NewRequest("POST", "https://api.apiverve.com/v1/textsimilarity", body)
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("x-api-key", "your_api_key_here")

	res, err := http.DefaultClient.Do(req)
	if err != nil {
		panic(err)
	}
	defer res.Body.Close()

	out, _ := io.ReadAll(res.Body)
	fmt.Println(string(out))
}

Replace your_api_key_here with the key from your dashboard. When the inputs arrive as a list rather than one at a time, batch requests run up to 200 of them through this same API in a single call.

Authentication

Send your key in the x-api-key header. That is the only auth step — there is no token exchange and no per-endpoint scope to configure. Authentication covers creating, rotating and revoking keys.

401 is the only auth verdict

A 401 means the key is missing, invalid or expired. A 403 means the key is valid but not permitted here — blocked by a key restriction or an IP allow-list. Running out of credits is a 429.

Parameters

Sent as JSON in the request body. Premium parameters are accepted on every plan but only take effect on plans that include them.

Parameter	Type	Description
`text1`Required	string	The first text to compare. Must be less than 1000 characters
`text2`Required	string	The second text to compare. Must be less than 1000 characters

Response

Every API returns the same three top-level keys, so one response handler covers your whole integration: status, error and data. Only data changes shape. Response format covers the envelope, the other output formats and how premium fields are withheld.

Sample response

{
  "status": "ok",
  "error": null,
  "data": {
    "simiarity": 45.83,
    "similarityCaseSensitive": 47.22,
    "difference": {
      "count": 7,
      "percentage": 58.33
    }
  }
}

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.

Field	Type	Example	Description
`simiarity`	number	`45.83`
`similarityCaseSensitive`	number	`47.22`
`difference`	object	`{...}`
`count`	number	`7`
`percentage`	number	`58.33`	Similarity percentage between 0 and 100

Errors

Read the HTTP status first, then error for the specific reason. The body names the parameter that has to change. Error handling covers the full status list and which of them are worth retrying.

Status	Meaning	What to do
`400`	Input was rejected	Read `error`; it names the parameter.
`401`	Key missing or invalid	Check the header name and the key value.
`403`	Key valid, but not permitted	A key restriction or IP allow-list; see key scoping.
`429`	Rate limited, or out of credits	Read `error` to tell them apart; see rate limits.

Use cases

Plagiarism Detection: Use the Text Similarity API to check for plagiarism in texts. Use the data to identify duplicate content and prevent academic dishonesty
Content Analysis: Analyze content by using the Text Similarity API to check the similarity between texts. Use the data to compare articles, essays, and research papers
Document Comparison: Compare documents by using the Text Similarity API to check the similarity between texts. Use the data to find similarities and differences in text content
Text Matching: Match text by using the Text Similarity API to check the similarity between texts. Use the data to find related content and improve search results

Other ways to use Text Similarity

Set up Text Similarity on APIVerve, or reach the same source a different way. Your APIVerve account and credits work on all of them — one key, one balance.

Give it to an AI agentConnect over MCP and your agent calls it as a native tool — Claude, Cursor, ChatGPT.VerveKit →Reference →

Use it in Google Sheets or ExcelA =VERVE() formula fills a column — no script, no export, recalculates in place.VerveSheets →Reference →

Text Similarity