Measure vocabulary sophistication: average word length, rare word percentage, CEFR vocabulary estimate, and ratio of common-to-advanced words. Highlights advanced vocabulary and surfaces jargon density.
Use when writing for non-native readers, simplifying technical docs, or checking that marketing copy isn't accidentally academic.
Pairs with Dale-Chall (which scores familiarity directly) and lexical density (information packing). All three together describe vocabulary load comprehensively.
Every word is bucketed as "everyday" (in the combined Dale-Chall + stopword list) or "advanced" (everything else).
CEFR estimate is derived from the advanced-word percentage: < 10% A1, < 20% A2, < 30% B1, < 45% B2, < 60% C1, else C2.
Jargon density is the percent of words ≥ 8 characters, a rough proxy for technical Latin/Greek-rooted vocabulary.
CEFR levels (A1, A2, B1, B2, C1, C2) describe reader vocabulary thresholds for non-native English learners. Higher = more advanced vocabulary load.
We use a combined list of English stopwords and the Dale-Chall 3,000 most familiar words. Anything outside is treated as advanced.
Not always. Audience-appropriate vocabulary beats clever-sounding vocabulary every time.
Input
The municipal infrastructure necessitates comprehensive remediation prior to subsequent occupancy.
Output
78% advanced — CEFR ~C2.
Seven of nine words fall outside the everyday vocabulary list, including Latin-rooted terms ("municipal", "necessitates", "remediation"). Average word length is over 9 characters.
% content words vs. function words.
analysisVocabulary variety — type‑token ratio.
analysisTotal + per‑word syllable counts.
analysisHighlight passive sentences in your writing.