Readability Scorer
Paste any text and get six readability scores, a consensus grade level, and a plain-language label.
Example: A paragraph averaging 25 words per sentence with frequent 3+ syllable words scores around a Flesch-Kincaid grade level of 14 (college level) — rewriting it to average 15 words per sentence with simpler vocabulary can drop that to grade level 8, roughly a 43% reduction in reading difficulty.
Uses the Flesch-Kincaid, Gunning Fog, SMOG, Coleman-Liau, and ARI readability formulas.
How readability is scored
Each formula estimates reading difficulty from sentence length and word/syllable complexity, using slightly different weightings. The consensus grade level averages five of the six scores (Flesch-Kincaid, Gunning Fog, SMOG, Coleman-Liau, and ARI) into one comparable figure, while Flesch Reading Ease is reported separately on its own 0–100 scale.
Use this alongside the Encoding Tools and JWT Decoder for content and developer workflows.
Frequently asked questions
- What is Flesch Reading Ease?
- A 0–100 score where higher means easier to read. It weighs average sentence length and average syllables per word — the two strongest predictors of reading difficulty in the original research.
- What grade level should I target?
- General audiences (news, marketing, most web content) read most comfortably at a 7th–9th grade level. Technical or academic writing can go higher; children's content should aim for 3rd–5th grade.
- Why do the scores disagree?
- Each formula weighs sentence length, word length, and syllable count slightly differently, so they rarely agree exactly. The consensus average grade level smooths out these differences into one comparable figure.
- Is SMOG reliable for short texts?
- SMOG was validated on 30-sentence samples — for shorter texts it extrapolates, which can skew the result. Treat SMOG on short texts as a rough indicator rather than a precise score.
- Can I use this via API?
- Yes — every calculator on Stupidly Clever has a matching REST API and MCP tool that runs the same underlying logic.