Text SimilarityText Similarity API

OnlineCredit Usage:1 per callRefreshed 1 month ago
avg: 1751ms|p50: 1593ms|p75: 1856ms|p90: 2171ms|p99: 2802ms

Text Similarity is a simple tool for checking the similarity between two texts. It returns the similarity score.

The Text Similarity API provides reliable and fast access to text similarity data through a simple REST interface. Built for developers who need consistent, high-quality results with minimal setup time.

To use Text Similarity, you need an API key. You can get one by creating a free account and visiting your dashboard.

POST Endpoint

URL
https://api.apiverve.com/v1/textsimilarity

Code Examples

Here are examples of how to call the Text Similarity API in different programming languages:

cURL Request
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!"
}'
JavaScript (Fetch API)
const response = 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!"
})
});

const data = await response.json();
console.log(data);
Python (Requests)
import requests

headers = {
    'X-API-Key': 'your_api_key_here',
    'Content-Type': 'application/json'
}

payload = {
    "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!"
}

response = requests.post('https://api.apiverve.com/v1/textsimilarity', headers=headers, json=payload)

data = response.json()
print(data)
Node.js (Native HTTPS)
const https = require('https');
const url = require('url');

const options = {
  method: 'POST',
  headers: {
    'X-API-Key': 'your_api_key_here',
    'Content-Type': 'application/json'
  }
};

const postData = 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!"
});

const req = https.request('https://api.apiverve.com/v1/textsimilarity', options, (res) => {
  let data = '';
  res.on('data', (chunk) => data += chunk);
  res.on('end', () => console.log(JSON.parse(data)));
});

req.write(postData);
req.end();
PHP (cURL)
<?php

$ch = curl_init();

curl_setopt($ch, CURLOPT_URL, 'https://api.apiverve.com/v1/textsimilarity');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'POST');
curl_setopt($ch, CURLOPT_HTTPHEADER, [
    'X-API-Key: your_api_key_here',
    'Content-Type: application/json'
]);

curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode({
    '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!'
}));

$response = curl_exec($ch);
curl_close($ch);

$data = json_decode($response, true);
print_r($data);

?>
Go (net/http)
package main

import (
    "fmt"
    "io"
    "net/http"
    "bytes"
    "encoding/json"
)

func main() {
    payload := map[string]interface{}{
        "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!"
    }

    jsonPayload, _ := json.Marshal(payload)
    req, _ := http.NewRequest("POST", "https://api.apiverve.com/v1/textsimilarity", bytes.NewBuffer(jsonPayload))

    req.Header.Set("X-API-Key", "your_api_key_here")
    req.Header.Set("Content-Type", "application/json")

    client := &http.Client{}
    resp, err := client.Do(req)
    if err != nil {
        panic(err)
    }
    defer resp.Body.Close()

    body, _ := io.ReadAll(resp.Body)
    fmt.Println(string(body))
}
Ruby (Net::HTTP)
require 'net/http'
require 'json'

uri = URI('https://api.apiverve.com/v1/textsimilarity')
http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = true

payload = {
  "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!"
}

request = Net::HTTP::Post.new(uri)
request['X-API-Key'] = 'your_api_key_here'
request['Content-Type'] = 'application/json'

request.body = payload.to_json

response = http.request(request)
puts JSON.pretty_generate(JSON.parse(response.body))
C# (HttpClient)
using System;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;

class Program
{
    static async Task Main(string[] args)
    {
        using var client = new HttpClient();
        client.DefaultRequestHeaders.Add("X-API-Key", "your_api_key_here");

        var jsonContent = @"{
        ""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!""
}";
        var content = new StringContent(jsonContent, Encoding.UTF8, "application/json");

        var response = await client.PostAsync("https://api.apiverve.com/v1/textsimilarity", content);
        response.EnsureSuccessStatusCode();

        var responseBody = await response.Content.ReadAsStringAsync();
        Console.WriteLine(responseBody);
    }
}

Authentication

The Text Similarity API requires authentication via API key. Include your API key in the request header:

Required Header
X-API-Key: your_api_key_here

Learn more about authentication →

Interactive API Playground

Test the Text Similarity API directly in your browser with live requests and responses.

Parameters

The following parameters are available for the Text Similarity API:

Check Similarity

ParameterTypeRequiredDescriptionDefaultExample
text1stringrequired
The first text to compare. Must be less than 1000 characters
-The quick brown fox jumps over the lazy dog
text2stringrequired
The second text to compare. Must be less than 1000 characters
-A fast brown fox leaps over a sleepy dog

Response

The Text Similarity API returns responses in JSON, XML, YAML, and CSV formats:

Example Responses

JSON Response
200 OK
{
  "status": "ok",
  "error": null,
  "data": {
    "simiarity": 45.83,
    "similarityCaseSensitive": 47.22,
    "difference": {
      "count": 7,
      "percentage": 58.33
    }
  }
}
XML Response
200 OK
<?xml version="1.0" encoding="UTF-8"?>
<response>
  <status>ok</status>
  <error xsi:nil="true" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"/>
  <data>
    <simiarity>45.83</simiarity>
    <similarityCaseSensitive>47.22</similarityCaseSensitive>
    <difference>
      <count>7</count>
      <percentage>58.33</percentage>
    </difference>
  </data>
</response>
YAML Response
200 OK
status: ok
error: null
data:
  simiarity: 45.83
  similarityCaseSensitive: 47.22
  difference:
    count: 7
    percentage: 58.33
CSV Response
200 OK
keyvalue
simiarity45.83
similarityCaseSensitive47.22
difference{count:7,percentage:58.33}

Response Structure

All API responses follow a consistent structure with the following fields:

FieldTypeDescriptionExample
statusstringIndicates whether the request was successful ("ok") or failed ("error")ok
errorstring | nullContains error message if status is "error", otherwise nullnull
dataobject | nullContains the API response data if successful, otherwise null{...}

Learn more about response formats →

Response Data Fields

When the request is successful, the data object contains the following fields:

FieldTypeSample ValueDescription
simiaritynumber45.83-
similarityCaseSensitivenumber47.22-
differenceobject{...}-
â”” countnumber7-
â”” percentagenumber58.33-

Headers

Required and optional headers for Text Similarity API requests:

Header NameRequiredExample ValueDescription
X-API-Keyrequiredyour_api_key_hereYour APIVerve API key. Found in your dashboard under API Keys.
Acceptoptionalapplication/jsonSpecify response format: application/json (default), application/xml, or application/yaml
User-AgentoptionalMyApp/1.0Identifies your application for analytics and debugging purposes
X-Request-IDoptionalreq_123456789Custom request identifier for tracking and debugging requests
Cache-Controloptionalno-cacheControl caching behavior for the request and response

Learn more about request headers →

GraphQL AccessALPHA

Access Text Similarity through GraphQL to combine it with other API calls in a single request. Query only the text similarity data you need with precise field selection, and orchestrate complex data fetching workflows.

Test Text Similarity in the GraphQL Explorer to confirm availability and experiment with queries.

Credit Cost: Each API called in your GraphQL query consumes its standard credit cost.

GraphQL Endpoint
POST https://api.apiverve.com/v1/graphql
GraphQL Query Example
query {
  textsimilarity(
    input: {
      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!"
    }
  ) {
    simiarity
    similarityCaseSensitive
    difference {
      count
      percentage
    }
  }
}

Note: Authentication is handled via the x-api-key header in your GraphQL request, not as a query parameter.

CORS Support

The Text Similarity API supports Cross-Origin Resource Sharing (CORS) with wildcard configuration, allowing you to call Text Similarity directly from browser-based applications without proxy servers.

CORS HeaderValueDescription
Access-Control-Allow-Origin*Accepts requests from any origin
Access-Control-Allow-Methods*Accepts any HTTP method
Access-Control-Allow-Headers*Accepts any request headers

Browser Usage: You can call Text Similarity directly from JavaScript running in the browser without encountering CORS errors. No proxy server or additional configuration needed.

Learn more about CORS support →

Rate Limiting

Text Similarity API requests are subject to rate limiting based on your subscription plan. These limits ensure fair usage and maintain service quality for all Text Similarity users.

PlanRate LimitDescription
Free5 requests/minHard rate limit enforced - exceeding will return 429 errors
StarterNo LimitProduction ready - standard traffic priority
ProNo LimitProduction ready - preferred traffic priority
MegaNo LimitProduction ready - highest traffic priority

Learn more about rate limiting →

Rate Limit Headers

When rate limits apply, each Text Similarity response includes headers to help you track your usage:

HeaderDescription
X-RateLimit-LimitMaximum number of requests allowed per time window
X-RateLimit-RemainingNumber of requests remaining in the current window
X-RateLimit-ResetUnix timestamp when the rate limit window resets

Handling Rate Limits

Free Plan: When you exceed your rate limit, Text Similarity returns a 429 Too Many Requests status code. Your application should implement appropriate backoff logic to handle this gracefully.

Paid Plans: No rate limiting or throttling applied. All paid plans (Starter, Pro, Mega) are production-ready.

Best Practices for Text Similarity:

  • Monitor the rate limit headers to track your Text Similarity usage (Free plan only)
  • Cache text similarity responses where appropriate to reduce API calls
  • Upgrade to Pro or Mega for guaranteed no-throttle Text Similarity performance

Note: Text Similarity rate limits are separate from credit consumption. You may have credits remaining but still hit rate limits when using Text Similarity on Free tier.

Error Codes

The Text Similarity API uses standard HTTP status codes to indicate success or failure:

CodeMessageDescriptionSolution
200OKRequest successful, data returnedNo action needed - request was successful
400Bad RequestInvalid request parameters or malformed requestCheck required parameters and ensure values match expected formats
401UnauthorizedMissing or invalid API keyInclude x-api-key header with valid API key from dashboard
403ForbiddenAPI key lacks permission or insufficient creditsCheck credit balance in dashboard or upgrade plan
429Too Many RequestsRate limit exceeded (Free: 5 req/min)Implement request throttling or upgrade to paid plan
500Internal Server ErrorServer error occurredRetry request after a few seconds, contact support if persists
503Service UnavailableAPI temporarily unavailableWait and retry, check status page for maintenance updates

Learn more about error handling →

Need help? Contact support with your X-Request-ID for assistance.

Integrate Text Similarity with SDKs

Get started quickly with official Text Similarity SDKs for your preferred language. Each library handles authentication, request formatting, and error handling automatically.

Available for Node.js, Python, C#/.NET, and Android/Java. All SDKs are open source and regularly updated.

Integrate Text Similarity with No-Code API Tools

Connect the Text Similarity API to your favorite automation platform without writing code. Build workflows that leverage text similarity data across thousands of apps.

All platforms use your same API key to access Text Similarity. Visit our integrations hub for step-by-step setup guides.

Frequently Asked Questions

How do I get an API key for Text Similarity?
Sign up for a free account at dashboard.apiverve.com. Your API key will be automatically generated and available in your dashboard. The same key works for Text Similarity and all other APIVerve APIs. The free plan includes 1,000 credits plus a 500 credit bonus.
How many credits does Text Similarity cost?

Each successful Text Similarity API call consumes credits based on plan tier. Check the pricing section above for the exact credit cost. Failed requests and errors don't consume credits, so you only pay for successful text similarity lookups.

Can I use Text Similarity in production?

The free plan is for testing and development only. For production use of Text Similarity, upgrade to a paid plan (Starter, Pro, or Mega) which includes commercial use rights, no attribution requirements, and guaranteed uptime SLAs. All paid plans are production-ready.

Can I use Text Similarity from a browser?
Yes! The Text Similarity API supports CORS with wildcard configuration, so you can call it directly from browser-based JavaScript without needing a proxy server. See the CORS section above for details.
What happens if I exceed my Text Similarity credit limit?

When you reach your monthly credit limit, Text Similarity API requests will return an error until you upgrade your plan or wait for the next billing cycle. You'll receive notifications at 80% and 95% usage to give you time to upgrade if needed.

What's Next?

Continue your journey with these recommended resources

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