Botoi Readability API vs UsingEnglish Text Analyser

Botoi Readability API analyzes English text and returns Flesch-Kincaid Grade, Flesch Reading Ease, Gunning Fog, and underlying counts. A request sends a required text string to POST /v1/text/readability and receives JSON. Flesch Reading Ease scores run from 0 to 100, with higher values indicating easier reading; Gunning Fog estimates the years of formal education needed. The formulas and syllable heuristics are calibrated for English, so grade mapping is not meaningful for other languages. Botoi recommends sending at least 100 words because short samples can produce unstable scores. Suggested uses include enforcing plain-language standards, reviewing legal or medical drafts, refining blog posts for SEO, and comparing writing across authors. Examples are provided in cURL, JavaScript, TypeScript, Python, and Go. The Free plan is free and lists 1,000 requests per day and 10 per minute; the endpoint page separately states five requests per minute for its free tier. Starter costs $9 a month. Requests above a per-minute or daily cap receive HTTP 429, and daily limits reset at midnight UTC.

UsingEnglish Text Analyser is a free web tool for examining text statistics, word patterns, and readability. The standard analyser counts words, different words, paragraphs, sentences, characters, and syllables, and reports hard-word and long-word measures plus the Gunning Fog Readability Index. It groups words by length with graphs and a frequency table, and produces a word cloud that scales terms by frequency while omitting very common words. The standard version handles up to 10,000 characters. The advanced analyser is also free, requires registration, accepts up to 100,000 characters, and can save up to 20 texts. Its tools include a sortable word-frequency list, word-length breakdown, graded text analysis, common-phrase analysis, and additional readability scores. Graded analysis compares vocabulary against the British National Corpus or General Service List, which can help when selecting vocabulary for learners. The standard analyser is described as suitable for students, translators, writers, and others who want to study text statistically.