Readability Checker
A free readability checker and reading level checker that scores any text with six trusted formulas: Flesch Reading Ease, Flesch-Kincaid Grade Level, Gunning Fog Index, SMOG Index, Coleman-Liau Index, and the Automated Readability Index. Paste your writing to see every readability score and reading level in one panel, then check the reading level of your text against the audience you are writing for. No signup, no limits, and the readability rating updates as you type.
Six readability formulas, one panel
Cross-reference scores to make confident editorial decisions.
6 readability scores
Flesch, Flesch-Kincaid, Gunning Fog, SMOG, Coleman-Liau, ARI.
Grade-level translation
Scores converted to US school grades for clarity.
Text statistics
Words, sentences, syllables, complex words, averages.
100% private
Analysis happens in your browser.
Free forever
No signup, no paywall, no usage limits.
Live updates
Every score updates as you type.
Who uses the Readability Checker?
Anyone writing for a specific audience.
For bloggers
Target Grade 7 to 9 for general audience. Spot when your writing gets too technical.
For SEO writers
Match reading level to your target audience. Google rewards readable content.
For technical writers
Verify documentation matches the user knowledge level you assume.
For educators
Match reading materials to student grade levels with confidence.
For journalists
Use the Gunning Fog score that journalism style guides recommend.
For medical writers
Use SMOG (the medical writing standard) to ensure patient materials are accessible.
About readability scores
What each formula measures and when to trust it.
What is a readability checker?
A readability checker is a tool that analyses written text and estimates how hard it is to read. Instead of guessing whether your writing is clear, you get a concrete readability score and a matching reading level, usually expressed as a US school grade. Our readability checker runs six separate formulas at once, so you can cross-reference results rather than relying on a single number. It works as a reading level checker for blog posts, essays, emails, marketing copy, technical documentation, and patient information leaflets, and it is completely free with no signup.
How readability scores are calculated
Most readability formulas measure two things: how long your sentences are and how complex your words are. Longer sentences and longer, multi-syllable words push the reading level up. The checker counts words, sentences, syllables, characters, and complex words, then feeds those numbers into each formula. Because each formula weights the inputs differently, a single piece of text can score slightly differently on each one. That is normal, and it is exactly why looking at all six scores together gives you a more reliable readability rating than any one formula alone.
Flesch Reading Ease
Flesch Reading Ease is the most widely used readability formula. The Flesch reading ease score ranges from 0 (very difficult) to 100 (very easy) and is computed from average words per sentence and average syllables per word. A score of 60 to 70 (Standard, around 8th to 9th grade) is the ideal range for general adult content, and most newspapers target this band. Academic papers often score 30 to 50, while content aimed at a wide audience can sit at 70 to 80 or higher. If you have only one number to watch, the Flesch reading ease score is a strong default.
Flesch-Kincaid Grade Level
Flesch-Kincaid readability uses the same input as Flesch Reading Ease but converts it into a US school grade. The Flesch-Kincaid reading level tells you the grade a reader needs to understand the text: Grade 8 means an average 8th grader can follow it, Grade 12 corresponds to a high school senior, and Grade 16 is college graduate level. The Flesch-Kincaid readability test is built into Microsoft Word and many publishing systems, so it is a practical benchmark when you need to target a specific audience reading level.
Flesch Reading Ease vs Flesch-Kincaid Grade Level
Flesch reading level can refer to either of the two Flesch metrics, so it helps to know the difference. Flesch Reading Ease gives a 0 to 100 score where higher is easier, which makes it good for quick editorial judgments. Flesch-Kincaid Grade Level gives a grade number where lower is easier, which makes it better for audience targeting and education. They are calculated from the same sentence-length and syllable data, so they will always agree on whether text is hard or easy. Use Reading Ease when you want a feel for clarity and the Flesch-Kincaid grade when you need a concrete reading level.
Gunning Fog Index
Developed by Robert Gunning in 1952 for journalism, the Gunning Fog Index counts complex words (3+ syllables) as a separate factor. A Gunning Fog score of 8 to 10 is ideal for newspapers and magazines, the Wall Street Journal averages around 11, and academic writing typically scores 14 to 20. Journalism style guides often cite Gunning Fog as their target, so it is a useful check if you write news, features, or general-interest articles.
SMOG Index
SMOG, the Simple Measure of Gobbledygook, was developed in 1969 for medical and government documents. It predicts the grade level needed to understand text based on the number of polysyllabic words. Healthcare materials and government forms are commonly required to meet SMOG 6 to 8, which is 8th grade or below. If you write patient information, consent forms, or public notices, SMOG is the readability formula regulators and health literacy experts tend to trust most.
Coleman-Liau Index
The Coleman-Liau Index was designed for computer analysis because it relies on characters per word rather than syllables, which are harder to count reliably. Its output is a US grade level. Because it only needs letters, words, and sentences, it works well for typed text and is used by automated readability scoring systems in CMS plugins and SEO tools.
Automated Readability Index (ARI)
The Automated Readability Index was originally developed for the US Army to assess technical manuals. Like Coleman-Liau, it uses characters per word rather than syllables, and its output is a US grade level. ARI is particularly useful for technical and military writing where readability needs to be measured automatically and at scale.
What is a good readability score?
There is no single good readability score, because the right reading level depends on your audience. For blog posts, marketing copy, and most web content, aim for a Flesch reading ease score of 60 to 80 and a grade level of 7 to 9, which matches how most adults read online. For content aimed at a broad general audience, Grade 5 to 6 is even safer. Academic, legal, and specialist technical writing will naturally score Grade 12 or higher, and that is acceptable when your readers expect it. The goal is not the lowest possible grade, but a readability rating that fits the people you are writing for.
How to improve your readability score
If your reading level is higher than you want, start with sentence length: break long sentences into two, and aim for an average of 15 to 20 words per sentence. Replace long, multi-syllable words with shorter everyday alternatives where the meaning allows. Cut filler phrases, use active voice, and prefer concrete nouns over abstract ones. Add paragraph breaks and lists to ease the visual load. After editing, paste your text back into the readability checker and watch the Flesch reading ease score rise and the grade level fall.
Why your score may differ from Grammarly or Word
Different tools count syllables and sentence boundaries in slightly different ways, so a Grammarly readability score or a Microsoft Word readability score will not always match ours exactly. The numbers should still land within a few points of each other for the same text, and they will agree on the overall trend. Our checker shows six formulas instead of one, which gives you a fuller picture than a single Flesch-Kincaid grade. If you need to match one specific tool, use that tool for the final figure and use our checker to verify and explore.
How to check the reading level of any text
To check the reading level of text, paste at least ten words into the box and read the results panel. The Flesch-Kincaid Grade Level and SMOG Index both report a US school grade directly, so you can see in seconds whether a passage suits a Grade 5, Grade 8, or college reader. The Flesch reading ease score adds a 0 to 100 view where higher means easier. Because every readability score recalculates as you type, you can paste a draft, spot the reading level, edit the hardest sentences, and watch the grade move. This makes the readability checker a fast reading level checker for a single paragraph or a full article.
Flesch reading ease score chart
The Flesch reading ease score maps to a reading difficulty band, and knowing the chart helps you set a target. A score of 90 to 100 is very easy and reads at roughly 5th grade. A score of 70 to 80 is fairly easy and suits 6th to 7th grade. A score of 60 to 70 is standard and matches 8th to 9th grade, the band most newspapers and general web content aim for. A score of 50 to 60 is fairly difficult, around 10th to 12th grade, and anything below 50 is difficult to very difficult, the range of academic and technical writing. Use the chart to translate a raw Flesch reading ease score into a concrete reading level.
What is a good readability rating for SEO content?
For SEO content, a good readability rating usually means a Flesch reading ease score of 60 to 80 and a Flesch-Kincaid reading level around Grade 7 to 9. Search engines do not publish a readability ranking factor, but content that matches how most people read tends to earn longer dwell time, lower bounce, and more shares, all of which support rankings indirectly. Aim for short sentences, plain words, and clear structure rather than chasing the lowest possible grade. Run your draft through the readability checker before publishing and adjust any section where the readability score drifts above your target.
Reading level checker for education and lesson planning
Teachers and curriculum designers use a reading level checker to match texts to a class. Paste a worksheet, article, or exam passage and the Flesch-Kincaid Grade Level and SMOG Index tell you the US grade a student needs to follow it. This makes it easy to confirm that a Grade 6 reading passage actually scores near Grade 6, or to grade a set of texts from easiest to hardest for differentiated instruction. Because the readability checker is free and runs instantly, you can compare several texts in a few minutes without installing anything.
Readability formulas compared at a glance
Each of the six formulas has a sweet spot. Flesch Reading Ease is the best quick gauge of overall clarity. Flesch-Kincaid Grade Level is the standard for audience targeting and is built into Microsoft Word. Gunning Fog suits journalism and penalizes long words directly. SMOG is the trusted choice for medical and government documents. Coleman-Liau and the Automated Readability Index rely on characters rather than syllables, so they are stable for automated and large-scale scoring. When the six readability scores agree, you can be confident in the reading level. When they diverge, check sentence length and complex-word count to find out why.
How to check readability
Three steps.
Paste at least 10 words
The scores need a minimum sample size to be meaningful.
Read all six scores
Cross-reference for a confident verdict.
Edit and recheck
Shorten sentences, swap complex words, paste again.
Match to audience
Grade 7 to 9 for general blogs. Grade 12 to 16 for academic.
Frequently asked questions
If you don't find your question here, ask us directly.
A readability score is a number that estimates how easy your text is to read. Most scores convert into a US school grade level (a Grade 8 score means an average 8th grader can understand the text). Lower grade levels mean easier text. Scores account for sentence length and word complexity. Different formulas produce slightly different results.
No single score is definitive. Use multiple scores together. Flesch Reading Ease is best for general readability. Flesch-Kincaid Grade is best for US school audiences. Gunning Fog matches journalism conventions. SMOG is preferred for medical and government documents. Our tool shows all six so you can cross-reference.
Aim for Grade 7 to 9 (Flesch Reading Ease 60 to 80). This matches how most adults read online. Going higher (Grade 5 to 6) makes content very easy, ideal for general audiences. Lower (Grade 10+) is appropriate for academic, technical, or specialised content. Always match the score to your audience.
Our tool uses a heuristic that counts vowel groups in each word, with adjustments for silent e at word endings and other common patterns. The result matches dictionary syllable counts about 90 to 95 percent of the time. Compound words and unusual spellings may be slightly off, but the impact on overall scores is small.
Word uses a slightly different syllable-counting algorithm and treats sentence boundaries differently in some edge cases. The scores should be within 5 to 10 points of each other for the same text. If you need to match Word exactly, paste your text into Word and use its built-in tool. For independent verification, our scores are reliable.
The formulas are calibrated for English. They will produce numbers for non-English text but the calibration will be off. For Spanish, the Fernandez-Huerta formula works similarly. For German, the Wiener Sachtextformel is standard. Our tool focuses on English. Use language-specific tools for other languages.
Both come from the same input (sentence length and word complexity) but produce different scales. Flesch Reading Ease ranges from 0 (very hard) to 100 (very easy). Flesch-Kincaid Grade outputs a US school grade number (Grade 8 means 8th grade reading level). Use Reading Ease for editorial decisions, Grade Level for audience targeting.
Yes. The readability checker runs entirely in your browser. Your text is never uploaded or logged. All six formulas are calculated using local JavaScript. Closing the tab clears the text from memory.
Paste your text into the readability checker and the tool instantly reports a reading level for each of its six formulas. The Flesch-Kincaid Grade Level and SMOG results map directly to a US school grade, so you can see at a glance whether your writing suits a Grade 7, Grade 9, or college-level reader. The scores update live, so you can edit and recheck the reading level as you go.
The Flesch reading ease score is a number from 0 to 100 that estimates how easy text is to read, where higher means easier. It is calculated from your average sentence length and average syllables per word. A score of 60 to 70 is considered standard and suitable for most adult readers, while a score above 80 is easy and a score below 50 is fairly difficult.
The Flesch-Kincaid readability test converts sentence length and word complexity into a US school grade level. A Flesch-Kincaid reading level of 8 means an average 8th grader can understand the text. It is one of the most widely recognised readability formulas because it is built into Microsoft Word and used across publishing, education, and government.
For newspapers, magazines, and general web content, a Gunning Fog score of 8 to 12 is a good target. Scores above 14 usually indicate academic or technical writing that demands a college-educated reader. The Gunning Fog Index is especially popular with journalists because it specifically penalises long, multi-syllable words.
Yes, this readability checker is completely free with no signup, no paywall, and no usage limits. You can check as much text as you like and run all six readability formulas every time. There is no premium tier, because the entire tool runs in your browser at no cost to us.
Yes. Educators often use it as a reading level checker to match texts to student grade levels. The Flesch-Kincaid Grade Level and SMOG Index both report a US grade, which makes it straightforward to confirm whether a passage suits the class you are teaching. Because results appear instantly, you can compare several texts in a few minutes.
Paste at least ten words into the readability checker and read the results panel. The Flesch-Kincaid Grade Level and SMOG Index report a US school grade directly, so you can tell at a glance whether the text suits a Grade 5, Grade 8, or college reader. The scores recalculate as you type, so you can edit and recheck the reading level in real time.
The Flesch reading ease score is a 0 to 100 number where higher means easier to read. Our tool calculates it from your average sentence length and average syllables per word and shows it in the results panel. A score of 60 to 70 is standard for general adult content, above 80 is easy, and below 50 is fairly difficult.
For most SEO and blog content, aim for a Flesch reading ease score of 60 to 80 and a Flesch-Kincaid reading level around Grade 7 to 9. Search engines do not publish a readability ranking factor, but readable content tends to hold attention longer and earn more engagement. Keep sentences short and words plain rather than chasing the lowest possible grade.
Grammarly reports a readability score based on the Flesch Reading Ease formula, the same family our tool uses. Because syllable counting and sentence detection vary slightly between tools, a Grammarly readability score may differ from ours by a few points. The overall trend and reading level will still agree, and our checker adds five more formulas for cross-reference.
The Flesch-Kincaid readability test converts sentence length and word complexity into a US school grade level, making it ideal for audience targeting. It is built into Microsoft Word and is widely used in publishing, education, and government to confirm that writing matches its intended reader. A Flesch-Kincaid reading level of 8 means an average 8th grader can understand the text.
Yes, this readability checker is completely free with no signup, no paywall, and no usage limits. You can check unlimited text and run all six readability formulas every time. The entire tool runs in your browser, so there is no cost to us and no premium tier.
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