All rules

Sentence too long

max-sentence-lengthon by default (info)Japanese / English

A sentence so long that the reader loses the subject before the verb

Example

Flagged
The new pricing, which the sales team proposed at last week's meeting, will be trialled from next month, but because we have not yet decided how to explain it to existing customers or when to change the billing system, we would like to agree on a plan this week.
What chaff prints
1:1 This sentence runs 49 words (limit 45)
Fixed
The new pricing will be trialled from next month. We have not yet decided how to explain it to existing customers, or when to change the billing system. We will agree on a plan this week.
What chaff prints
no finding

How to fix

Split it in two at the conjunction.

Why it matters

In a long sentence the reader loses the subject before reaching the verb.

What it does not flag

Headings, table cells and code are not counted, nor is a line that only lists names or titles with 、 and has no full stop (an attendee list), nor are the page markers a converted print edition leaves inside a sentence ("( printed page 52044)", "[[Page 52044]]"). A footnote that is a bibliographic citation (authors (2025), "Title," publisher) counts only the words the writer puts before it ("For example, see …"). A 「」 quotation holding two or more sentences closed by 。 is measured sentence by sentence, apart from the words around it. Genres where long sentences are normal (statutes, papers) raise the limit.

Turning it off or relaxing it

Silence this one spot (in the document)
<!-- stet: max-sentence-length — reason -->
Relax it for the team (the reason is kept as a comment in chaff.yaml)
npx chaffjs relax max-sentence-length --why "reason"
Turn it off for the team (chaff.yaml)
rules: max-sentence-length: off
Technical details
Layer
L1
Status
stable
Severity
info
Languages
Japanese and English
Suited to
blog, business, technical, legal, docs, academic, literature, speech

Levels

Set a level for this rule under rules in chaff.yaml. With nothing set, it runs at the level its genre gives it (see By genre below).

strictup to 18 words in a sentence
normalup to 25 words in a sentence
relaxedup to 35 words in a sentence

These genres set their own numbers for the levels (npx chaffjs explain shows them): technical, blog, blog/essay, business, business/email, docs, legal, legal/statute, legal/judgment, academic

By genre

Runs by default in
technical/spec, technical/readme, blog/tech, blog/essay, blog/owned-media, business/proposal, business/report, business/email, business/press-release, business/meeting-notes, docs/manual, docs/faq, docs/glossary, speech/address
Turned off by the genre in
legal/contract, legal/statute, legal/judgment, legal/patent, academic/paper, literature/fiction, literature/essay, literature/poetry, literature/play, speech/transcript

Genres

Message

This sentence runs {count} words (limit {limit})

This English sentence runs {count} words (limit {limit})

This Japanese sentence runs {count} characters (limit {limit})

Rewrite depth (chaff fix-plan --depth): light — words and sentences; the structure and the voice stay

Sources

This page is built from the rule's definition file:packages/chaff/rules/max-sentence-length.yaml