Readabiliy Scores API

Get various readability scores for a given text.

Enhance Content Clarity with Readability Scores API

Make your content accessible to everyone with our Readability Scores API—an advanced tool that analyzes text readability and ensures your message resonates with your target audience.

Why Choose Our API?

Comprehensive Readability Metrics: Get insights from industry-standard readability formulas, including Flesch-Kincaid, Gunning Fog, SMOG, and more.

• Instant Analysis: Process text in real-time and receive instant feedback on readability.
• Versatile Integration: Easily integrate into your apps, CMS platforms, and workflows via a simple API.
• Improve Engagement & SEO: Optimize content readability to boost user retention and search rankings.
• Supports Multiple Languages: Analyze text in various languages to enhance global accessibility.

Who Can Benefit?

• Content Marketers & SEO Experts: Ensure your content is digestible and ranks higher.
• Developers & SaaS Platforms: Integrate readability scoring into your applications.
• Educators & Publishers: Tailor content to the appropriate reading level.
• Journalists & Writers: Enhance readability and audience engagement.

API End Points

The end point for connecting : If you subscribe directly from us use this endpoint.

	https://api.interfaces.one

API Documentation

To get readability scores for a given text use the following API endpoint.

   GET /readability/scores

   Parameters
       text={text}

The above call will generate a response like the one below.

{
    "success": {
        "total": 13
    },
    "contents": [
        {
            "name": "Flesch-Kincaid Reading Ease",
            "score": 48.8,
            "description": "The Flesch-Kincaid Reading Ease score is the result of a mathematical formula that incorporates the average number of syllables per word and the average number of words per sentence for a 100-word block of text. Results are measured on a scale of 1-100 (1 is the hardest and 100 is the easiest.). This is one of the oldest readability scores, commonly used in academics and government and incorporated into most word processing software. "
        },
        {
            "name": "Flesch-Kincaid Grade Level",
            "score": 9.7,
            "description": "Like the Flesch- Kincaid Reading Ease score, this is a mathematical formula that measures syllables and sentence length. However, the results are given as an academic grade level, from 0-12. Usually your goal is 7th-8th grade as that encompasses about 80% of US adults."
        },
        {
            "name": "Coleman-Liau Index",
            "score": 12,
            "description": "The Coleman-Liau Index is a readability formula that estimates the grade level needed to understand a piece of text. Unlike other readability formulas, it uses letters per word and sentences per word instead of syllables or word length.  The formula looks like this: CLI=0.0588L\u22120.296S\u221215.8\nWhere:\n    L = Average number of letters per 100 words.\n    S = Average number of sentences per 100 words."
        },
        {
            "name": "Gunning-Fog score",
            "score": 11.7,
            "description": "The Gunning Fog Index takes into account \u201ccomplex\u201d words, those with three or more syllables, as part of its mathematical formula for readability. It gives a grade-level score from 1-unlimited. Ideal score is between 7-8."
        }, {
            "name": "SMOG Index",
            "score": 11.8,
            "description": "The SMOG Index (Simple Measure of Gobbledygook) is a readability formula that predicts the years of education someone needs to understand a piece of text. It focuses on the complexity of words by counting the number of polysyllabic words (words with three or more syllables) in a given section of text."
        }, {
            "name": "Automated Readability Index",
            "score": 9.5,
            "description": "The Automated Readability Index (ARI) is a readability formula used to estimate the grade level required to understand a text. It's based on the average word length (measured in characters) and sentence length (measured in words), making it easy to calculate with modern tools."
        }, {
            "name": "Dale-Chall readability score",
            "score": 6.7,
            "description": "The Dale-Chall Readability Score is a readability formula that assesses the difficulty of a text based on sentence complexity and the familiarity of words. It uses a specially designed list of 3,000 common, easy-to-understand words. Words not on this list are considered \"difficult.\""
        }, {
            "name": "Spache readability score",
            "score": 4.9,
            "description": ""
        }, {
            "name": "Average words per sentence",
            "score": 13,
            "description": ""
        }, {
            "name": "Average syllables per word",
            "score": 1.71,
            "description": ""
        }, {
            "name": "3 Syllable words Percentage",
            "score": "17.31%",
            "description": ""
        }, {
            "name": "Total words",
            "count": 104,
            "description": "Total word count"
        }, {
            "name": "Reading Time",
            "count": 1,
            "description": "Approx. Reading Time in minutes"
        }
    ],
    "copyright": {
        "url": "interfaces.one",
        "year": "2025"
    }
}

Ratelimiting

Some of our API calls may be public(requires free API key) , while others requires paid subscription. To maintain our serice levels both public and private API endpoints are ratelimited. Please consult your specific plan that you subscribed to for the rate limit details.

Authentication

Currently we support API Key based authentication. Please set your Autorization Bearer request header with value of your API key. Alternatively you can also pass api_key= as a request parameter, though we strongly discourage this mode of passing the key, since it will allow others to see your key.

In curl this would mean sending the Authorization header like below.

            
 curl -i <url> -H "Authorization: Bearer <api_key>"
            
            

If you are using PHP.

            
$authorization = "Authorization: Bearer <api_key>";
$ch = curl_init('<url>'); // Initialise cURL
curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: application/json' , $authorization ));
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST"); // OR GET
$result = curl_exec($ch);
curl_close($ch);
            
            

In javascript you can use headers key to add the authorization header

            
$.ajax({
   url: '<url>'
   type: 'GET',
   contentType: 'application/json'
   headers: {
      'Authorization': 'Bearer <api_key>'
   },
   success: function (result) {
       // CallBack(result);
   },
   error: function (error) {

   }
});