Docs/APIs/Website Readability

Website Readability

Analyze Website Readability

OperationalCredits 5 per callp50 1798msText ProcessingStar

Overview

Website Readability works by fetching the page, extracting its readable text and scoring it across standard readability indices (Flesch, Gunning Fog, SMOG, Coleman-Liau, ARI, Dale-Chall). It also reports the word and sentence counts, an estimated reading time, an averaged grade level and the target reader audience so you can judge a page's accessibility at a glance.

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/websitereadability
curl -X POST https://api.apiverve.com/v1/websitereadability \
  -H "x-api-key: your_api_key_here" \
  -H "Content-Type: application/json" \
  -d '{
  "url": "https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/concepts"
}'
const res = await fetch('https://api.apiverve.com/v1/websitereadability', {
  method: 'POST',
  headers: {
    'x-api-key': 'your_api_key_here',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
  "url": "https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/concepts"
}),
});

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/websitereadability",
    headers={"x-api-key": "your_api_key_here"},
    json={
    "url": "https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/concepts"
},
    timeout=15,
)
res.raise_for_status()

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

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

func main() {
	body := strings.NewReader(`{
  "url": "https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/concepts"
}`)
	req, _ := http.NewRequest("POST", "https://api.apiverve.com/v1/websitereadability", 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.

ParameterTypeDescription
urlRequiredstringThe URL of the web page to analyze
url

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": {
    "fleschReadingEase": 24.34,
    "fleschReadingEaseText": "Very Confusing",
    "fleschKincaidGrade": 19.3,
    "gunningFog": 19.62,
    "colemanLiauIndex": 13.12,
    "smogIndex": 14.37,
    "automatedReadabilityIndex": 22.6,
    "daleChallReadabilityScore": 17,
    "daleChallReadabilityScoreText": "average 13th to 15th-grade (college) student",
    "wordCount": 634,
    "sentenceCount": 29,
    "readingTimeMinutes": 3,
    "averageGradeLevel": 17.8,
    "targetAudience": "post-graduate",
    "url": "https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/concepts"
  }
}

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
fleschReadingEasenumber24.34Flesch Reading Ease score (0-100, higher is easier)
fleschReadingEaseTextstring"Very Confusing"Descriptive text interpretation of Flesch Reading Ease
fleschKincaidGradenumber19.3Flesch-Kincaid Grade Level (US school grade equivalency)
gunningFogPremiumnumber19.62Gunning Fog Index (years of education needed to understand)
colemanLiauIndexPremiumnumber13.12Coleman-Liau Index (US grade level based on character count)
smogIndexPremiumnumber14.37SMOG Index (years of education to understand text)
automatedReadabilityIndexPremiumnumber22.6Automated Readability Index (US grade level estimate)
daleChallReadabilityScorePremiumnumber17Dale-Chall Readability Score (educational level)
daleChallReadabilityScoreTextPremiumstring"average 13th to 15th-grade (college) student"Descriptive interpretation of Dale-Chall Readability Score
wordCountnumber634Number of words in the page's readable text
sentenceCountnumber29Number of sentences in the page's readable text
readingTimeMinutesnumber3Estimated reading time in minutes at an average adult reading speed of 238 words per minute
averageGradeLevelPremiumnumber17.8Single averaged US school grade level digested from the grade-based indices (Flesch-Kincaid, Gunning Fog, Coleman-Liau, SMOG, ARI) — the one number that summarizes how much education a reader needs
targetAudiencePremiumstring"post-graduate"Reader band mapped from the average grade level: elementary, middle school, high school, college, post-graduate or general public
urlstring"https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/concepts"The analyzed URL from the request

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.

Other ways to use Website Readability

Set up Website Readability 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 →
Use it in Google Sheets or ExcelA =VERVE() formula fills a column — no script, no export, recalculates in place.VerveSheetsReference →

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