Docs/APIs/Text Similarity

Text Similarity

Check text similarity

OperationalCredits 2 per callp50 1593msText ProcessingStar

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!"
}'

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.

ParameterTypeDescription
text1RequiredstringThe first text to compare. Must be less than 1000 characters
text2RequiredstringThe 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.

FieldTypeExampleDescription
simiaritynumber45.83
similarityCaseSensitivenumber47.22Case-sensitive similarity score between the two texts, as a percentage from 0 to 100, where differing letter casing counts against the score
differenceobject{...}
countnumber7Number of words that appear in only one of the two texts, counted across both directions
percentagenumber58.33Percentage of words, out of the combined word count of both texts, that appear in only one of the two texts

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.

StatusMeaningWhat to do
400Input was rejectedRead error; it names the parameter.
401Key missing or invalidCheck the header name and the key value.
403Key valid, but not permittedA key restriction or IP allow-list; see key scoping.
429Rate limited, or out of creditsRead error to tell them apart; see rate limits.

Use cases

Plagiarism Screening
Educators check student assignment submissions against reference essays to catch paraphrased or near-identical passages using case-insensitive similarity scores.
Catalog Deduplication
To merge duplicate inventory listings, marketplace operators evaluate difference percentages across submitted product titles.
Support Ticket Clustering
Helpdesk systems group incoming user inquiries with existing knowledge base answers when match percentages cross predefined thresholds.
Translation Revision Tracking
When editors revise translated copy, localization teams compute case-sensitive similarity to track how much phrasing changed between drafts.

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.VerveKitReference →
Google Sheets or ExcelA =VERVE() formula fills a column — no script, no export, recalculates in place.VerveSheetsReference →

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