Text Analysis & Comparison API

What it does

Text Analysis API helps you measure readability, compare strings, and check basic document formatting from plain text inputs. Send text and get structured results back for writing analysis, review workflows, or content QA.

Use /text/readability to submit a text string and receive readability scores including fleschReadingEase, fleschKincaidGrade, avgWordsPerSentence, avgSyllablesPerWord, wordCount, sentenceCount, and an interpretation. That makes it useful when you need to flag hard-to-read content, tune copy for a target audience, or track whether edits made writing simpler.

Use /text/similarity to compare two strings, a and b, and get distance, ratio, and percent similarity. The output is suited to duplicate detection, change checks, or quick editorial comparison when you need a numeric measure of how close two passages are.

Use /security/diff to compare textA and textB line by line. It returns added, removed, equal, and a lines array with each line marked as equal, add, or remove, plus line numbers where available. Use /text/paper-format to check a text string for words, paragraphCount, hasTitleLikeHeading, hasDoubleSpacingHint, and notes when you need a lightweight formatting review.

▣ ENDPOINT 01 / 04

POST

Readability Score (Flesch)

https://api.eu.apyhub.com/freedailypro/text-analysis-comparison-api/text/readability

QUICKSTART

GUIDE

Quickstart

Send a text sample to get a readability analysis.

curl -X POST "https://api.eu.apyhub.com/freedailypro/text-analysis-comparison-api/text/readability" \
  -H "apy-token: $APY_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"text":"The quick brown fox jumps over the lazy dog. This short paragraph is easy to read."}'

What you'll get back

The live response to the request above:

{
  "tool": "Reading level checker client and server side from freedailypro",
  "result": {
    "fleschReadingEase": 87.7,
    "fleschKincaidGrade": 3,
    "avgWordsPerSentence": 8,
    "avgSyllablesPerWord": 1.31,
    "wordCount": 16,
    "sentenceCount": 2,
    "interpretation": "Easy (6th grade)"
  }
}

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API key

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The full key is used to call the gateway and stays in this tab — never sent to orbit or saved.

About this endpoint

What it does

Scores how easy a piece of English text is to read. It returns the Flesch Reading Ease score (higher is easier), the Flesch–Kincaid grade level, average words per sentence, average syllables per word, word and sentence counts, and a plain-language reading level such as "Very Easy (5th grade)". Use it to check content for a target audience before publishing.

Request Body

Parameter	Type	Mandatory	Description
text	String	Yes	The text to analyze for readability.

Response

A successful call returns a JSON object with these fields:

Parameter	Type	Description
tool	String	Name of the tool that produced the response.
result	Object	Readability scores.
result.fleschReadingEase	Number	Flesch Reading Ease score; higher is easier to read.
result.fleschKincaidGrade	Number	Flesch–Kincaid US school grade level.
result.avgWordsPerSentence	Number	Average number of words per sentence.
result.avgSyllablesPerWord	Number	Average number of syllables per word.
result.wordCount	Number	Number of words.
result.sentenceCount	Number	Number of sentences.
result.interpretation	String	Plain-language reading level.

▣ ENDPOINT 02 / 04

POST

Text Similarity & Edit Distance

https://api.eu.apyhub.com/freedailypro/text-analysis-comparison-api/text/similarity

QUICKSTART

GUIDE

Quickstart

Compare two text strings by sending them as a and b.

curl -X POST "https://api.eu.apyhub.com/freedailypro/text-analysis-comparison-api/text/similarity" \
  -H "apy-token: $APY_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"a":"Machine learning is fun.","b":"Machine learning is enjoyable."}'

What you'll get back

The live response to the request above:

{
  "tool": "Text similarity client and server side from freedailypro",
  "result": {
    "distance": 9,
    "ratio": 0.7,
    "percent": 70
  }
}

TRY ITLIVE · 10 ATOMS

API key

Loading your default key…

The full key is used to call the gateway and stays in this tab — never sent to orbit or saved.

About this endpoint

What it does

Compares two strings and returns the edit distance (the number of single-character changes needed to turn one into the other) and how similar they are as a ratio and a percentage. The comparison is case-sensitive. Use it for fuzzy matching, typo detection and finding duplicate entries.

Request Body

Parameter	Type	Mandatory	Description
a	String	Yes	The first input string to compare.
b	String	Yes	The second input string to compare.

Response

A successful call returns a JSON object with these fields:

Parameter	Type	Description
tool	String	Name of the tool that produced the response.
result	Object	Similarity between the two strings.
result.distance	Number	Levenshtein distance: the number of single-character edits needed to turn `a` into `b`.
result.ratio	Number	Similarity from 0 to 1, where 1 means identical.
result.percent	Number	Similarity as a percentage.

▣ ENDPOINT 03 / 04

POST

Line-by-Line Text Diff

https://api.eu.apyhub.com/freedailypro/text-analysis-comparison-api/security/diff

QUICKSTART

GUIDE

Quickstart

Compare two text inputs for a security diff by sending both strings in a JSON body.

curl -X POST "https://api.eu.apyhub.com/freedailypro/text-analysis-comparison-api/security/diff" \
  -H "apy-token: $APY_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "textA": "The system stores customer data in a database.",
    "textB": "The system stores customer data in an encrypted database."
  }'

What you'll get back

The live response to the request above:

{
  "tool": "Diff checker client and server side from freedailypro",
  "result": {
    "lines": [
      {
        "type": "add",
        "line": "The system stores customer data in an encrypted database.",
        "lineNumberB": 1
      },
      {
        "type": "remove",
        "line": "The system stores customer data in a database.",
        "lineNumberA": 1
      }
    ],
    "added": 1,
    "removed": 1,
    "equal": 0
  }
}

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API key

Loading your default key…

The full key is used to call the gateway and stays in this tab — never sent to orbit or saved.

About this endpoint

What it does

Compares two texts line by line, like a code diff. Each line is marked as equal, add (only in textB) or remove (only in textA), with its line numbers, and the response includes totals for added, removed and unchanged lines. Use it to compare document versions, config files or content changes.

Request Body

Parameter	Type	Mandatory	Description
textA	String	Yes	The first text to compare.
textB	String	Yes	The second text to compare.

Response

A successful call returns a JSON object with these fields:

Parameter	Type	Description
tool	String	Name of the tool that produced the response.
result	Object	Line-by-line comparison.
result.lines	Array of Object	Every line from both texts, in order.
result.lines[].type	String	`equal`, `add` (only in `textB`) or `remove` (only in `textA`).
result.lines[].line	String	The line content.
result.lines[].lineNumberB	Number	Line number in `textB`. Absent for `remove` lines.
result.lines[].lineNumberA	Number	Line number in `textA`. Absent for `add` lines.
result.added	Number	Number of added lines.
result.removed	Number	Number of removed lines.
result.equal	Number	Number of unchanged lines.

▣ ENDPOINT 04 / 04

POST

Paper Formatting Checker

https://api.eu.apyhub.com/freedailypro/text-analysis-comparison-api/text/paper-format

QUICKSTART

GUIDE

Quickstart

Send the text you want checked for paper-format issues in a single JSON body.

curl -X POST "https://api.eu.apyhub.com/freedailypro/text-analysis-comparison-api/text/paper-format" \
  -H "apy-token: $APY_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"text":"This is a sample academic paragraph for format checking."}'

What you'll get back

The live response to the request above:

{
  "tool": "Paper format checker client and server side from freedailypro",
  "result": {
    "words": 9,
    "hasTitleLikeHeading": true,
    "hasDoubleSpacingHint": false,
    "paragraphCount": 1,
    "notes": [
      "Heuristic only — not a full APA/MLA layout engine."
    ]
  }
}

TRY ITLIVE · 10 ATOMS

API key

Loading your default key…

The full key is used to call the gateway and stays in this tab — never sent to orbit or saved.

About this endpoint

What it does

Runs a quick heuristic check on a text's paper formatting: word count, paragraph count, title-like heading and double spacing. It is not a full APA/MLA validator.

Request Body

Parameter	Type	Mandatory	Description
text	String	Yes	The text to analyze.

Response

A successful call returns a JSON object with these fields:

Parameter	Type	Description
tool	String	Name of the tool that produced the response.
result	Object	Formatting checks.
result.words	Number	Number of words.
result.hasTitleLikeHeading	Boolean	`true` if the text starts with a title-like heading.
result.hasDoubleSpacingHint	Boolean	`true` if the text appears to use double spacing.
result.paragraphCount	Number	Number of paragraphs.
result.notes	Array of String	Notes about the check.

▣ COMMON ERRORS

Errors any endpoint can return

400bad_request

Required parameter missing or malformed body.

401unauthorized

API key missing, revoked, or not authorized for this service.

429rate_limited

Your plan's per-second rate exceeded. Retry with exponential backoff.

503upstream_busy

Backend temporarily unavailable. Try again in a few seconds.

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From the blog

Reads that touch this API.

Readability Score solutions for developers: Libraries and APIsJul 9, 2026 What is the Readability Score? Meaning and Use CasesJul 9, 2026 Top Tools, APIs and Use Cases for Extracting Text from Any WebsiteAug 10, 2026 Text Summarization API: A Developer's Guide to AI Summarization in 2026Sep 15, 2026