Free sentence complexity analyzer. Measures average clause depth, subordinate clause count, simple / compound / complex sentence classification, passive voice rate, and surfaces the longest parse-like structures.
Use when your text feels hard to read but you can't pinpoint why. A high clause depth combined with high passive count is the classic recipe for "dense" prose.
Where readability formulas give a single grade, this tool tells you what *kind* of complexity drives it — subordination, coordination, or length.
Each sentence is tokenized and counted for subordinating connectives ("because", "although"), coordinating connectives ("and", "but"), and passive constructions.
Clause depth is roughly 1 + subordinate clause count. Sentences with no connectives are "simple"; with only coordination they're "compound"; with any subordination they're "complex".
Splits surfaced are sentences over 35 words or with three or more subordinate clauses — typical candidates for trimming.
Roughly how many clauses each sentence contains. A sentence with two subordinate clauses has depth 3.
Not directly — use a readability formula for that. This tool is about syntactic complexity, which can be high in clear writing or low in unclear writing.
Heavy passive voice and deep subordination both increase parsing load. The split suggestions surface sentences that combine both.
Input
Although the meeting ran long, we covered every agenda item. Decisions were made. The team left energized.
Output
Avg clause depth: 1.67 — Simple. Mix: 2 simple, 0 compound, 1 complex.
One subordinate clause ("Although the meeting ran long") gives sentence 1 a depth of 2; the other two are depth 1. The blend reads as varied but accessible.
% content words vs. function words.
analysisVocabulary variety — type‑token ratio.
analysisTotal + per‑word syllable counts.
analysisHighlight passive sentences in your writing.