Readability Analyzer: Flesch, Fog, SMOG for pages and text

Give it page URLs, text you paste, or both, and it returns six readability scores for each one, the counts behind them, a reading time, and the sentences and words that make the text hard to read.

What you get for each text or page

• Six scores: Flesch reading ease, Flesch Kincaid grade level, Gunning fog index, SMOG grade, Coleman Liau index and the automated readability index (ARI), plus the average of the five grade level scores.
• The counts behind them: words, sentences, syllables, characters, letters and digits, words of three or more syllables, complex words, average words per sentence and average syllables per word.
• Reading time in minutes and seconds, at 200 words per minute or the speed you set.
• Where to start editing: the longest sentences with their word counts, and the complex words used most often.
• Dictionary coverage: the share of words whose syllables came from the CMU Pronouncing Dictionary. The rest are counted by spelling rules.
• A SMOG check: smogReliable is false when the text has fewer than 30 sentences, the sample size the SMOG formula was built on.

How the scores are worked out

• Flesch reading ease: 206.835 minus 1.015 × (words ÷ sentences) minus 84.6 × (syllables ÷ words)
• Flesch Kincaid grade: 0.39 × (words ÷ sentences) + 11.8 × (syllables ÷ words) minus 15.59
• Gunning fog: 0.4 × ((words ÷ sentences) + 100 × (complex words ÷ words))
• SMOG: 1.0430 × √(words of three or more syllables × 30 ÷ sentences) + 3.1291
• Coleman Liau: 0.0588 × letters per 100 words minus 0.296 × sentences per 100 words minus 15.8
• ARI: 4.71 × (letters and digits ÷ words) + 0.5 × (words ÷ sentences) minus 21.43

Complex words for the fog index have three or more syllables, not counting an -es, -ed or -ing ending as a syllable, and leave out hyphenated compounds and capitalized words inside a sentence (taken as proper nouns). Words are runs of letters, so a number on its own is not counted as a word.

Sentences end at a full stop, question mark or exclamation mark followed by a capital letter, a digit or the end of the line. Common abbreviations such as Dr., e.g. and p.m. do not end a sentence. In pasted text and in page text, every line break also ends a sentence, so headings and list items count as sentences. In a plain text file (a URL served as text/plain) only a blank line ends a paragraph, so lines wrapped at a fixed width are joined back up.

For a page, the main text is scored: menus, headers and footers are left out. Turn on "Include the text" to see exactly what was scored.

English text only.

Input

• Page URLs, one text, more texts as a JSON list (strings, or objects with an id and a text), or any mix
• Reading speed (default 200 words per minute)
• Longest sentences and complex words to list (default 5)
• Include the text (default off)
• Pages at once (default 5) and page timeout (default 30 seconds)

Output

Dataset: one item per text or page with id, url, finalUrl and title for pages, the six scores, averageGrade, the counts, readingTimeMinutes, readingTimeSeconds, smogReliable, dictionaryCoverage, longestSentences, topComplexWords, and ok.

A text or page that cannot be scored returns an item with ok: false and the reason, such as HTTP 404, a file that is not a page or text (an image, for example), or a text with no English words. The rest of the run carries on.

Export as JSON, CSV or Excel, or read it over the API.

Pricing

Pay per event: one event per text or page scored. A text or page that fails is not charged. The run stops when it reaches the maximum charge you set.

Scope and conduct

Only the URLs you list are fetched. Links are not followed. No login is used.

Support

Questions and problems: the Issues tab on this page. Replies are written by an AI assistant on behalf of the developer and reviewed by the developer.