Readability Checker

What is the Readability Checker?

The Readability Checker is a free online tool that measures how hard your English text is to read and tells you who can comfortably read it. Paste or type any passage and it instantly reports six well-known readability scores plus a single overall grade level, so you can see at a glance whether your writing suits a wide audience or only specialist readers. It is built for anyone who writes for other people and wants their message to land on the first read.

This readability checker runs entirely in your browser, so your text never leaves your device. That matters when the thing you are checking is confidential — an unpublished article, a client email under NDA, an internal report, or a draft you simply do not want sitting on someone else's server. Nothing is uploaded, logged, or saved.

How to use it

1. Type directly into the text box, or paste an email, article, paragraph, or whole document.
2. Watch the scores update live as you type — there is no button to press.
3. Read the overall grade level and the plain-language difficulty label to judge your audience.
4. Skim the improvement suggestions, edit the longest sentences and hardest words, and watch the score climb.

The point is a one-second answer: drop in your text, read the grade, fix the two or three things it flags, and move on.

The formulas behind the numbers

Every score is computed locally from three simple inputs: how many words you used, how long your sentences are, and how many syllables your words carry. The tool reports six standard formulas because each one weighs those inputs a little differently, and seeing them together is more trustworthy than relying on any single number.

• Flesch Reading Ease rates text from 0 to 100, where higher is easier. A score of 60 to 70 is plain English that most adults read comfortably; below 30 is dense, academic prose.
• Flesch-Kincaid Grade Level converts that ease score into a US school grade, so a result of 8.0 means an average eighth-grader can read it.
• Gunning Fog Index estimates the years of formal education a reader needs, and it pays special attention to the proportion of long, complex words.
• SMOG Index predicts the grade level from the count of three-or-more-syllable words and is popular for health and safety writing.
• Coleman-Liau Index works from letters per word and words per sentence rather than syllables, which makes it robust on text full of numbers or unusual spelling.
• Automated Readability Index (ARI) also uses characters and sentence length and was originally built for real-time grading on early electronic typewriters.

Syllables are estimated with a vowel-group heuristic rather than a shipped dictionary: the tool counts runs of consecutive vowels, drops a silent trailing e, and adds one back for common endings like -le. It is approximate for any single word but averages out accurately across a paragraph.

Examples

• The sentence "The cat sat on the mat." scores near the top of the reading-ease scale and lands around a 1st-grade level — short words, one short sentence.
• A typical news paragraph with sentences of fifteen to twenty words and a few longer words lands around a Flesch Reading Ease of 60 to 65 and an eighth-to-ninth-grade level, which is the sweet spot for general audiences.
• A dense legal or academic passage with thirty-word sentences and many polysyllabic terms can drop below a reading-ease of 30 and climb past a college grade level, signalling that you should split sentences and simplify vocabulary.

Common use cases

• Content writers and bloggers aiming for the plain, scannable style that performs well in search.
• Students and academics checking whether an essay matches the register an assignment expects.
• Marketers and UX writers making sure landing pages, emails, and microcopy are effortless to read.
• Health, legal, and government communicators who must hit a mandated reading level so the public can understand important information.
• Editors giving authors a fast, objective second opinion on clarity.

Why use this readability checker

Most readability tools online show a single number from a single formula, which can be misleading when that formula happens to flatter or punish your particular style. This checker shows six formulas at once and a combined grade level, so you get a reliable verdict instead of one noisy data point. It runs entirely in your browser, which means your text is never uploaded and the scores appear the instant you stop typing — safe for confidential drafts and fast on mobile. On top of the raw scores it gives a plain-language difficulty label and concrete suggestions, so you know not just how hard your text is but exactly what to change.

It is part of a small, focused text toolkit. Use the Word Counter when you need exact word, character, and sentence totals, the Character Counter for strict tweet and bio limits, and the Reading Time Calculator to estimate how long your finished piece takes to read.

Frequently asked questions