Readability Checker

Find out how easy your writing is to read

Readability Checker scores English text with six standard formulas — Flesch Reading Ease, Flesch–Kincaid Grade, Gunning Fog, SMOG, Coleman–Liau and the Automated Readability Index — and sums them up as an approximate US school grade and reader age. It also highlights the sentences long enough to make readers work.

The scores are estimates designed for English. They measure sentence length and word length, not whether the text makes sense, so treat them as a prompt to look again rather than a verdict. Your text is analysed in your browser and never uploaded.

How to check the readability of a text

1. Paste or type your text into the box. At least three words are needed; a few paragraphs give steadier scores.
2. Wait a moment — the results update shortly after you stop typing.
3. Read the headline Reading Ease score and the grade-level summary under it.
4. Scroll to Long sentences to see which sentences are marked, then shorten or split them in your original and paste it again.

Reading the scores

• Flesch Reading Ease: usually 0 to 100, higher is easier, with a plain-language band from Very easy to Very difficult. Very short, simple text can score above 100.
• Grade levels: Flesch–Kincaid, Gunning Fog, SMOG, Coleman–Liau and ARI each estimate the US school grade needed to follow the text. Very simple text can give a grade below zero.
• Summary: the average of the grade-level scores, shown as “about US grade X — roughly age Y”.
• SMOG: only calculated from 30 sentences, the sample size it was designed for; below that it says how many more are needed.
• Long sentences: over 20 words are marked amber and labelled Long; over 30 words red and labelled Very long, with the word count beside each.

When a readability score is useful

• Web copy: check that product pages, help articles and FAQs suit a general audience.
• Public information: aim for plain English in letters, forms and instructions.
• Teaching material: compare a text’s level with the age of the class.
• Editing drafts: find the sentences to split first, then proofread with the Grammar Checker.

How the counts are made

Words and sentences

Words are runs of letters or digits, so “don’t”, “well-known” and “3.5” each count once. Sentences end at a full stop, question mark or exclamation mark followed by a space, and at every line break, so headings and list items count as sentences. Abbreviations such as “Dr.”, “Mr.” and “e.g.”, initials and decimals don’t end a sentence; “etc.” and “U.S.” end one only when a capital letter follows.

Syllables and complex words

Syllables are estimated with spelling rules rather than a dictionary: groups of vowels are counted, then a silent final e, -es and -ed endings, -le endings and vowel pairs that are usually said separately (as in “media”) are adjusted, with a short list of exceptions. On lists of common words it is right almost every time, but names and rare words can be off by one. Numbers count as one syllable.

For Gunning Fog, complex words are words of three or more syllables, leaving out hyphenated words, capitalised words in mid-sentence (usually names) and words that only reach three syllables through an -ed, -es or -ing ending.

Readability Checker: common questions