Free Tool
Readability Score for Documentation
Paste markdown or a docs URL — get a clear readability score plus the standard Flesch-Kincaid Reading Ease and Grade Level, heading depth, sentence length, and acronym density. Then Gemini rewrites your worst-reading section so you can see what better looks like. Hemingway-style, but tuned for technical writing.
How it works
Input
URL or markdown — we strip code blocks, lists, and tags before analyzing prose.
Score
Flesch-Kincaid, structural breakdown, and a 0-100 docs-tuned composite.
Rewrite
Gemini 2.5 Flash Lite rewrites the worst section so you can see what better reads like.
Want this baked into your docs site?
Docsio generates a branded documentation site from your URL in minutes — with llms.txt, schema markup, and AI-friendly structure already built in.
Try Docsio FreeFAQ
Documentation readability checker: common questions
What metrics does the docs readability checker use?
It runs Flesch Reading Ease and Flesch-Kincaid Grade Level on every page, plus heading depth, average sentence length, passive voice ratio, and a jargon density score tuned for technical writing. Scores are calculated per page and rolled up to a site average so you can spot the worst offenders fast.
What is a good readability score for documentation?
For technical docs, aim for a Flesch Reading Ease score between 50 and 70 and a Grade Level around 8 to 11. Going lower can dumb down API docs in ways that break accuracy. Going higher usually means long sentences and stacked jargon that lose readers, especially evaluators and non-native English speakers.
How do I improve documentation readability?
Cut sentences over 25 words, prefer active voice, replace unexplained acronyms on first use, break long paragraphs into lists or steps, and front-load the answer in the first two sentences of each section. The tool flags the lowest-scoring passages and shows an AI rewrite you can copy as a starting point.
Is the readability checker free?
Yes, the checker is free with no signup and no rate limit. Paste a URL or markdown and you get the full report instantly. Docsio also runs readability checks on every page inside the editor, so customers writing docs on Docsio see scores as they write rather than after publish.
What tools compete with this readability checker?
General-purpose options include Hemingway Editor, Grammarly, and Readable.com, all aimed at marketing copy or essays. This tool is built specifically for documentation: it understands code blocks, ignores them from prose scoring, weighs headings, and benchmarks against other docs sites rather than blog posts.