Sentence Length Analyser

There is no single ideal sentence length — the right length depends on the audience, the purpose, and the genre. For web content aimed at general audiences, most style guides suggest an average of 15-20 words per sentence, with regular variation. The Hemingway Editor flags sentences over 30 words as hard to read. Yoast SEO flags sentences over 20 words as too long for easy online reading. Academic writing routinely uses sentences of 25-30 words without issue. The most important principle is variety: a mix of short and long sentences creates natural rhythm, while uniform sentence length — regardless of whether it is short or long — makes prose feel monotonous.

Very long sentences — generally over 35 words — become difficult to follow because they require the reader to hold multiple clauses in working memory simultaneously. By the time the reader reaches the end of the sentence, they may have lost track of where it started. Long sentences are also harder to skim, which is a significant problem for web content where readers rarely read every word. If you have sentences consistently over 35 words, look for natural break points — places where a full stop or a split into two sentences would make the structure clearer.

Yes. Sentences under 5 words — particularly in a long sequence — create a choppy, telegraphic quality that feels abrupt and can obscure the logical relationships between ideas. A series of very short sentences can read like a list of facts rather than a reasoned argument. That said, short sentences are powerful used deliberately and sparingly: a 3-word sentence after several long ones creates emphasis through contrast. The problem is using them exclusively or in long runs without variation.

Sentence length variation is a surprisingly reliable signal of writing maturity. Inexperienced writers tend to write in one register — either uniformly short (from fear of complexity) or uniformly long (from trying to sound academic). Skilled writers vary sentence length deliberately, using short sentences for emphasis and long sentences to develop ideas with nuance. The bar chart this tool produces makes this rhythm immediately visible: a healthy piece of writing looks like a varied skyline; a problematic one looks like a flat plain or a single tall spike.

The most reliable method is to look for conjunctions — "and," "but," "which," "that," "because," "although" — and consider whether the sentence would be clearer split at that point. "The proposal was reviewed by the board, which had concerns about the timeline, and it was sent back for revision" can become two sentences: "The board reviewed the proposal and raised concerns about the timeline. They sent it back for revision." Another technique is to look for relative clauses ("which," "that," "who") and convert them into separate sentences. Aim to have a clear subject and verb within the first 15-20 words of any long sentence.