Overview
Readability Score works by analyzing the text provided and calculating the readability score. It uses advanced algorithms to calculate the readability score based on various readability formulas and returns the readability score.
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.
curl -X POST https://api.apiverve.com/v1/readabilityscore \
-H "x-api-key: your_api_key_here" \
-H "Content-Type: application/json" \
-d '{
"text": "Western astrology is founded on the movements and relative positions of celestial bodies such as the Sun, Moon and planets, which are analysed by their movement through signs of the zodiac (twelve spatial divisions of the ecliptic) and by their aspects (based on geometric angles) relative to one another."
}'const res = await fetch('https://api.apiverve.com/v1/readabilityscore', {
method: 'POST',
headers: {
'x-api-key': 'your_api_key_here',
'Content-Type': 'application/json',
},
body: JSON.stringify({
"text": "Western astrology is founded on the movements and relative positions of celestial bodies such as the Sun, Moon and planets, which are analysed by their movement through signs of the zodiac (twelve spatial divisions of the ecliptic) and by their aspects (based on geometric angles) relative to one another."
}),
});
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/readabilityscore",
headers={"x-api-key": "your_api_key_here"},
json={
"text": "Western astrology is founded on the movements and relative positions of celestial bodies such as the Sun, Moon and planets, which are analysed by their movement through signs of the zodiac (twelve spatial divisions of the ecliptic) and by their aspects (based on geometric angles) relative to one another."
},
timeout=15,
)
res.raise_for_status()
print(res.json()["data"])package main
import (
"fmt"
"io"
"net/http"
"strings"
)
func main() {
body := strings.NewReader(`{
"text": "Western astrology is founded on the movements and relative positions of celestial bodies such as the Sun, Moon and planets, which are analysed by their movement through signs of the zodiac (twelve spatial divisions of the ecliptic) and by their aspects (based on geometric angles) relative to one another."
}`)
req, _ := http.NewRequest("POST", "https://api.apiverve.com/v1/readabilityscore", 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.
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.
| Parameter | Type | Description |
|---|---|---|
textRequired | string | The text to calculate the readability score of |
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.
{
"status": "ok",
"error": null,
"data": {
"textCounts": {
"syllableCount": 82,
"lexiconCount": 49,
"sentenceCount": 1
},
"readability": {
"fleschReadingEase": 13.28,
"fleschKincaidGrade": 23.6,
"gunningFog": 26.95,
"colemanLiauIndex": 13.19,
"smogIndex": 22.08,
"automatedReadabilityIndex": 27.8,
"daleChallReadabilityScore": 17
},
"readabilityText": {
"fleschReadingEase": "very confusing",
"daleChallReadabilityScore": "average 13th to 15th-grade (college) student"
},
"averageGradeLevel": 22.7,
"targetAudience": "post-graduate"
}
}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.
| Field | Type | Example | Description |
|---|---|---|---|
textCounts | object | {...} | |
syllableCount | number | 82 | |
lexiconCount | number | 49 | |
sentenceCount | number | 1 | |
readability | object | {...} | |
fleschReadingEase | number | 13.28 | |
fleschKincaidGrade | number | 23.6 | |
gunningFog | number | 26.95 | |
colemanLiauIndex | number | 13.19 | |
smogIndex | number | 22.08 | |
automatedReadabilityIndex | number | 27.8 | |
daleChallReadabilityScore | number | 17 | |
readabilityText | object | {...} | |
fleschReadingEase | string | "very confusing" | |
daleChallReadabilityScore | string | "average 13th to 15th-grade (college) student" | |
averageGradeLevel | number | 22.7 | Average grade level from all metrics |
targetAudience | string | "post-graduate" | Suggested target audience based on readability |
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.
| Status | Meaning | What to do |
|---|---|---|
400 | Input was rejected | Read error; it names the parameter. |
401 | Key missing or invalid | Check the header name and the key value. |
403 | Key valid, but not permitted | A key restriction or IP allow-list; see key scoping. |
429 | Rate limited, or out of credits | Read error to tell them apart; see rate limits. |
Use cases
- Content Analysis
- Use the Readability Score API to calculate the readability score of text for content analysis. Use the data to analyze language, extract insights, and improve comprehension
- Language Processing
- Calculate readability score by using the Readability Score API for language processing. Use the data to analyze grammar, categorize text, and enhance understanding
- Content Generation
- Use the Readability Score API to calculate the readability score of text for content generation. Use the data to create variations, improve readability, and enhance engagement
- Text Analysis
- Calculate readability score by using the Readability Score API for text analysis. Use the data to analyze language, extract insights, and improve comprehension
Other ways to use Text Readability Score
Set up Text Readability Score on APIVerve, or reach the same source a different way. Your APIVerve account and credits work on all of them — one key, one balance.
Related
More in Text Processing: