Readability scores estimate how hard a text is to read, by measuring things that are easy to count, such as the length of sentences and the length of words. A text with short sentences and short words scores as easy to read, and a text with long sentences and long words scores as hard. The scores are not a verdict on quality. A technical book can be difficult for good reasons, and a children's story can be short and simple on purpose. They are a way to check that the difficulty of your writing matches the reader you have in mind.
Free tool · Readability Score Checker
Readability Score Checker that shows how easy your writing is to read
The readability score checker measures a passage with six well-known formulas, Flesch Reading Ease, Flesch-Kincaid grade level, Gunning Fog, SMOG, Coleman-Liau and the Automated Readability Index, and explains the result in plain English, with an optional comparison against a target grade for your readers. It runs in your browser, keeps your text on your device and is free for authors, bloggers, students and teachers.
Use the free tool
The readability score checker is free to use, with no account and nothing uploaded.
- Six readability scores
- Genre grade targets
- Plain-English reading
Key facts
- FreeNo cost, no account and no usage limit on the readability score checker
- In your browserNothing that you type or paste into the readability score checker is uploaded
- SecondsTypical time from opening the readability score checker to a result
Free tool
Readability score checker
Paste a passage to see Flesch Reading Ease, Flesch-Kincaid grade level and four other readability scores, with a plain-English reading of the result.
The readability score checker needs JavaScript, and it works in your browser without sending anything that you enter to a server.
Overview
What the readability score checker does and why it helps
This checker runs six formulas at once because each has its strengths. Flesch Reading Ease gives a score from 0 to 100, where higher is easier, and plain text for the general public often falls between 60 and 70. Flesch-Kincaid gives a US school grade, so a result of 8 means that an average eighth grader could follow the text. Gunning Fog, SMOG, Coleman-Liau and the Automated Readability Index give their own grade estimates, using the share of long words and the length of sentences in different ways.
Use the scores to compare drafts of the same text and to check a draft against a target. If you are writing for a broad adult audience, a grade of around 7 to 9 is a common aim, and for a children's book it will be far lower. When a passage scores higher than you want, the usual remedy is to shorten sentences and swap long words for plain ones, and when it scores lower than you want for an expert audience, there may be room to add precision. Paste at least thirty words, since shorter samples give unreliable scores.
The readability score checker measures how easy your text is to read, using standard formulas such as Flesch Reading Ease and grade level. Authors can use this free readability score checker as often as they like, and it never asks for payment. Open the readability score checker online and it is ready at once, with no download. Use it as a readability score checker free online whenever you are mid-project. The wording and defaults suit a readability score checker for authors, not general business users. If you publish independently, treat it as a readability score checker for self-published books of any length. If you publish on Amazon, use it as a readability score checker for KDP too, since it follows that platform's rules. As a readability score checker no sign up page, it asks for no email and sets no account. As a readability score checker tool for writers it keeps the language plain and the steps short. If you are hunting for the best readability score checker, judge it by whether it explains its numbers, as this one does.
Some authors use a readability score checker Grammarly includes in its editor. This page is a separate option that gives the same standard scores without an account.
How to use it
How to use the readability score checker, step by step
Paste your text
Copy a passage of a few hundred words or more. Short samples give unreliable results, because the formulas depend on sentence and word length averaged over enough text to be meaningful.
Choose a target audience
Optionally choose the grade level of your readers. The tool then compares your score with the target and tells you whether your text is easier or harder than the audience expects.
Press check
The tool applies six formulas to the same text: Flesch Reading Ease, Flesch-Kincaid grade, Gunning Fog, SMOG, Coleman-Liau and the Automated Readability Index.
Read the summary
Each score is explained in plain English, with a grade level or an ease rating. Look at where the formulas agree, which is more informative than any one number alone.
Find the long sentences
The tool highlights the longest sentences and the hardest words, which are the usual causes of a high grade level. Fix those first, since they give the biggest change.
Revise and recheck
Shorten sentences and choose simpler words where they help, then paste the revision and compare the scores. Stop when the text suits your readers, not when a number hits a target.
How the readability score checker works
Six well-known formulas, one clear reading
The tool counts the words, sentences and syllables in your passage, and the letters in each word, then applies six formulas: Flesch Reading Ease, Flesch-Kincaid grade level, Gunning Fog, SMOG, the Automated Readability Index and Coleman-Liau. Each uses sentence length and word length in a different way, so together they give a balanced picture.
Flesch Reading Ease gives a score from 0 to 100, where higher is easier, and the tool translates it into a band such as plain English or fairly difficult. The other scores give an approximate school grade, which you can compare with a target that you choose for children's fiction, popular fiction, nonfiction or academic writing.
Readability scores measure surface features, not quality. A short sentence can be confusing, and a long one can be clear. Use the numbers as a prompt to check sentence length and word choice, and remember that dialogue, jargon and your readers' background all matter.
- Six formulas, one report
- A target grade for your genre
- A plain-English reading of the ease score
Method
How the readability score checker works out its answer
Flesch Reading Ease
The score is 206.835 minus 1.015 times the average sentence length in words, minus 84.6 times the average number of syllables per word. Higher scores mean easier text.
Flesch-Kincaid grade level
The grade is 0.39 times the average sentence length plus 11.8 times the average syllables per word, minus 15.59, which gives a US school grade.
Gunning Fog and SMOG
Gunning Fog adds the average sentence length to the percentage of long words with three or more syllables and multiplies by 0.4. SMOG counts words of three or more syllables over a set of sentences and takes a square root.
Coleman-Liau and ARI
These two use letters per word instead of syllables, which makes them easy to compute. Coleman-Liau uses letters and sentences per 100 words, and the Automated Readability Index uses characters per word and words per sentence.
Tips
Getting the most from the readability score checker
Use a sample of at least 200 words
The scores settle as the text grows, and a longer sample gives a fairer picture of your usual style. The readability score checker is free and instant, so it is worth running again whenever your book changes.
Compare with books you admire
Paste a published passage from a book in your genre to see its level. It gives you a reference that is more useful than a general rule.
Read the long sentences first
They are the quickest route to easier prose. Splitting one long sentence often lowers the grade more than replacing several words. A few minutes with the readability score checker now saves time across the whole manuscript.
Need it done for you?
When the readability score checker is not enough
The checker tells you how readable the words are. These services make the page readable too, with the type, spacing and structure that help readers at every level.
Nonfiction Book Formatting
A nonfiction formatter turns clear writing into a clear page, with headings, callouts and tables that help readers move through the book.
See the service →Educational Book Formatting
Educational books depend on readability, and a specialist sets the type, spacing and structure so that learners can follow along.
See the service →Large Print Book Formatting
Large print editions make the text easier to read for people who need bigger type, with generous spacing and a careful layout.
See the service →Before and after
Before and after using the readability score checker
The same explanation, first written in long sentences and long words and then revised for the grade of the readers.
123Before
- 1Long sentences that readers lose track of
- 2A grade level far above the audience
- 3No way to measure a revision
123After
- 1Shorter sentences that are easy to follow
- 2A grade level that fits the readers
- 3Scores that show whether a rewrite helped
- 3problems found in the first review
- 3fixes checked in the final review
- 1named specialist owning every fix
- Fixedprice confirmed in the calculator before you order
Clearer sentences
Long sentences are split and loaded phrases are made plain, so readers understand the point on the first pass.
The right level
The grade matches your audience, whether that is beginners, general readers or specialists.
Evidence of progress
Six scores show whether a revision made the passage easier, so you stop guessing.
Client reviews
What authors say about our readability edit service
Verified reviews from authors who asked a specialist to handle the readability edit after using the readability score checker.
As a first-time author, the technical side of self-publishing was genuinely daunting. The consultation covered every decision — platform choice, pricing strategy, metadata, and distribution. I launched with genuine confidence.
Navigating IngramSpark's requirements for the first time felt overwhelming. The upload assistance handled everything — metadata, pricing setup, distribution channels. My children's book reached bookstores within two weeks.
The formatting error fix service saved my launch. My original formatter had made margin errors causing repeated rejection. Book Formatting Experts identified and fixed every issue within 48 hours. My launch was back on schedule.
My YA novel needed to reach both English-language and Japanese readers. The multi-region distribution setup was handled correctly across all required platforms. International sales have exceeded my expectations.
Good support throughout the KDP upload process. The metadata setup and category selection were explained clearly. One pricing setting needed adjustment after initial setup but it was corrected quickly.
Good publishing support overall. The KDP metadata setup was thorough. One category selection needed updating after initial launch but it was corrected promptly. The book is performing well in its target categories.
My KDP file was rejected with a technical error message I could not understand. Book Formatting Experts diagnosed the problem immediately — a bleed issue on three pages — and corrected it the same day. Approved first time.
Getting historical fiction placed in the right categories on Amazon and IngramSpark required strategic metadata. The team understood the genre classification and the book reached the right readers from the first week.
The publishing readiness review identified four issues in my manuscript that would have caused rejection. Each was clearly explained and quickly resolved. My book launched without any technical complications.
My cookbook needed to be set up across multiple platforms simultaneously. The publishing support team handled every submission — KDP, IngramSpark, and Apple Books — with different requirements for each. Flawlessly executed.
The romantic atmosphere of the cover design is exactly right for my readership. The colour temperature, the typography, and the visual composition all signal the genre clearly without being generic.
Good formatting work on my early reader book. The large font and generous spacing were applied correctly. One illustration needed repositioning in revisions but it was fixed quickly. Happy with the result.
My book blended speculative and literary elements that needed sensitive typographic treatment. Every unconventional element was handled with understanding and real precision. A genuinely impressive result.
The world-building section of my website gives readers a proper introduction to my universe before they even open the first book. It is exactly what a fantasy series needs. Beautifully structured and genuinely immersive.
The reflowable EPUB looks perfect on every device I tested — Kindle, Apple Books, and Kobo. The clickable table of contents and chapter navigation work exactly as they should.
The Kindle file looks professional on every device I have tested it on. Consistent fonts, clean line spacing, and the table of contents navigates properly. My readers have noticed the improvement over my previous book.
The cover communicates tension and danger without revealing too much of the plot. The design is original rather than using standard genre conventions. It stands out distinctively on Amazon search pages.
Every intentional white space, line break, and stanza pause survived the formatting process exactly as I had written them. Poetry is where formatting can make or break the reading experience. This got it right.
More free tools
More free tools to use with the readability score checker
Each of these tools is free, runs in your browser and works well alongside the readability score checker.
Word Count Tool
Free word count tool that works in your browser, plus a done-for-you manuscript length check service with your readability edit.
Open the tool →Adverb Passive Voice Checker
Free adverb passive voice checker that works in your browser, plus a done-for-you adverb and passive edit service for the readability edit.
Open the tool →Filler Word Finder
For your readability edit, free filler word finder that works in your browser, plus a done-for-you filler word edit service.
Open the tool →Book Blurb Analyzer
Free book blurb analyzer that works in your browser, plus a done-for-you blurb edit service.
Open the tool →Word Frequency Analyzer
For your readability edit, free word frequency analyzer that works in your browser, plus a done-for-you repetition edit service.
Open the tool →Dialogue Ratio Calculator
For your readability edit, free dialogue ratio calculator that works in your browser, plus a done-for-you dialogue balance review service.
Open the tool →FAQ
Readability Score Checker: questions answered
These are the questions authors ask most about the readability score checker, including accuracy, privacy and what to do next. If your question about the readability edit is missing, request a quote and a specialist will reply.
What is a readability score checker?
It is a tool that measures how easy a text is to read, using formulas based on sentence length and word length, and reports scores such as Flesch Reading Ease and grade level.
What is a good Flesch Reading Ease score?
Scores between 60 and 70 are considered plain English and suit a broad adult audience. Higher is easier, and lower is harder.
What is the Flesch-Kincaid grade level?
It estimates the US school grade needed to understand the text, so a score of 8 means an eighth grader could follow it.
What reading level should I write at?
Many books for a general adult audience sit between grades 6 and 9. Children's books are lower, and specialist texts may be higher.
Why are there six scores?
Each formula weighs the features differently, so comparing them gives a more reliable picture than one score.
How many words do I need to paste?
At least thirty, and more is better. Short samples give unreliable scores.
Does a low grade mean the writing is simple or poor?
No. Clear writing about complex topics can score low in grade and still be excellent. The score measures sentence and word length only.
How can I lower the grade of my writing?
Split long sentences, use shorter words where they mean the same thing and avoid stacking clauses.
Does the tool work in other languages?
The formulas are designed for English, so the scores are not reliable for other languages.
Does the readability score checker keep anything that I enter?
No. The readability score checker works in your browser, so what you enter stays on your device and is never saved.
Can I use it for fiction?
Yes, but dialogue and fragments pull the scores down, so use it to compare passages and not to judge a book.
Is the readability score checker free?
Yes, the readability score checker costs nothing, needs no account and puts no limit on the passages you check.
Why do the five formulas disagree?
Each one weights different features. Coleman-Liau counts letters and never looks at syllables, so it handles unusual names better. Gunning Fog and SMOG hinge on the share of three-syllable words. Wide disagreement usually points to something distinctive, such as heavy dialogue or a burst of proper nouns.
How accurate is the syllable counting?
The vowel-group method with silent-e handling agrees with a dictionary for roughly nineteen out of twenty ordinary English words. Invented names, foreign borrowings and unusual compounds are where it slips, which matters little once you are scoring a few hundred words.
Does dialogue affect my score?
Considerably. Dialogue is built from short sentences and short words, so heavy dialogue pushes reading ease up and grade level down. Score narrative passages separately from dialogue-driven ones if you want a fair picture of your descriptive writing.
What is the difference between Flesch and Flesch-Kincaid?
They use the same two inputs but scale them differently. Reading Ease produces a number from roughly 0 to 100 where higher means easier, while Flesch-Kincaid converts the same measurements into a United States school grade, where higher means harder.
How does a readability score checker work?
It counts sentences, words and syllables, then applies the Flesch formulas to give a score and a grade level.
How to use a readability score checker?
Paste a passage, press check and compare the score with the typical level for your genre.
Is there a readability score checker with examples?
Yes. The page includes a worked example so you can compare it with your own numbers or text. Compare a passage from your book with a children's chapter to see the gap.
Work with a specialist
Turn what you learn from the readability score checker into a finished book
The readability score checker costs nothing, and so does asking what a specialist would do with your book. When the readability score checker has done its part and you want finished files, a fixed price and one named person who owns the job, we are ready to start.