Readability checkerValidators

Readability checker. Flesch score and grade.

Paste English text and see the Flesch reading ease score, the Flesch-Kincaid grade level, words per sentence and every sentence over the length you pick. Scores are estimates. Nothing leaves your browser.

Cost to you

Free

Runs in your browser. No signup, no API call, no limit per hour.

browser
runs in: none
API calls: none
account

Use it now

Use the Readability checker here

It runs in your browser. Nothing you type is sent anywhere, there is no signup and no limit.

Scores

Flesch reading ease: 90
Flesch-Kincaid grade: 5.2

Easy. Higher ease means easier text; the grade is the US school year that can read it.

Words per sentence: 17.8
Syllables per word: 1.17
Words of 3+ syllables: 2.8%
Sentences: 6

Long sentences (1)

30 wordsLeave a thumb's width of room at the toe, because your foot slides forward on every descent and a tight shoe bruises toenails after a long day in the hills.

Formulas: reading ease = 206.835 - 1.015 x (words / sentences) - 84.6 x (syllables / words); grade = 0.39 x (words / sentences) + 11.8 x (syllables / words) - 15.59. Syllables are estimated, so scores can differ by a few points from other checkers. Built for English. Runs in your browser, nothing is sent anywhere.

Run it from your agent

Copy one prompt, give it to your agent.

Fill in the placeholder, paste it, and the agent runs the same job with current data on your looot account and shows the cost.

You give it: english text.
Billed per call, nothing while your agent is idle.
The agent shows the price before it calls.

Prompt: Readability checker

Use looot to check the readability of [page URL]. 1. Set up https://looot.ai/skill.md. 2. Search the catalog for a web page to markdown endpoint and check its price before you call. 3. Read the page text and work out its Flesch reading ease and Flesch-Kincaid grade. 4. Return both scores, the five longest sentences and a shorter rewrite of each.

Give this to your agent

Setup command

set up looot for Readability checker - https://looot.ai/free-tools/readability-checker/skill.md

What comes back

What your agent gets from readability checker

Field names as the providers return them. The exact set varies by endpoint, and your agent reads it from the catalog.

Flesch reading ease score
Flesch-Kincaid grade level
average words per sentence
share of words with three or more syllables
list of long sentences

Providers

Who can do this job today

Your agent picks the endpoint. These providers offer one right now, with the live price of their cheapest.

Context.dev$0.0025 / call

Cheapest priced endpoint of each provider, read from the looot catalog. Cheapest overall: $0.0025 per call.

Use it for

What people do with readability checker

Edit a draft
Find the long sentences that make a post hard to read and split them.
Web pages
Check that a landing page reads at the level your visitors expect.
Plain language
Check letters, policies and help pages before they go out.
Audit a site
Have your agent score every page and list the hardest to read.

Set up once

Three steps. Your agent does the rest.

Paste one prompt into your agent

Set up looot

Done, looot is connected.

Copy one prompt from /connect into Claude Code, Cursor, or any MCP agent. No SDK, no dashboard click-through first.

Your agent finds the right operation

Hunter$0.0265

Exa$0.0090

Diffbot$0.0032

The agent finds the operation it needs and sees the price first. It calls nothing blind.

You watch what it cost

Hunter$0.0265

Exa$0.0090

Diffbot$0.0032

Total$0.0387

Every call settles for its quoted price and lands in the ledger. You always know what ran and what it cost.

Keep going

Calculators
Word counter
Words, characters, sentences, paragraphs, reading and speaking time, and your top words, as you type.
Free, no signupno limit
SEO
Keyword density checker
Density tables for one, two and three word phrases, a target keyword count and a flag over 3 percent.
Free, no signupno limit
Research
AI text analyzer
Summary, sentiment, topics and intents with scores for a short English text, from one real API call.
Runs a real API call$0.0010 / call

FAQ

Questions about readability checker

60 to 70 reads as plain English for most adults. Higher is easier: 90 and above is very easy, and under 30 is very difficult and suits specialists.

It is the US school grade that can read the text. A grade of 8 means a typical eighth grader, about 13 or 14 years old, can follow it.

With Flesch's published formulas, from words per sentence and syllables per word. Both formulas are printed under the result.

Syllables are estimated with a vowel-group rule, and tools split sentences differently, so scores can differ by a few points. Compare drafts in the same tool.

Every sentence over the limit you pick: 20, 25 or 30 words. They are listed longest first, so you fix the worst ones first.

No. The formulas and the syllable rule are built for English. Other languages need their own formulas.

No. The checker runs in your browser and sends your text nowhere.

Yes. It needs no account and has no limit.

For agents

tool: Readability checker
category: Validators
input: English text
output: Flesch reading ease score, Flesch-Kincaid grade level, average words per sentence, share of words with three or more syllables, list of long sentences
endpoint: context-dev: context-dev-web-scrape-markdown
price: per call, read live from the catalog on the web page
web tool: runs in the visitor's browser, no API call, free and unlimited
schedule: on demand
setup: https://looot.ai/free-tools/readability-checker/skill.md
llms.txt: https://looot.ai/llms.txt
updated: 2026-10-14

markdown /free-tools/readability-checker.md

Run readability checker from your own agent.

Start your workspace, top up, and paste the prompt into the agent you already use. It runs the job with live data and shows the cost first.

Start your workspace See all free tools