Sentence Length Checker

The number that hides the problem

Every sentence counter gives you two figures: the average length and the longest sentence. Both are useful and neither tells you why a page is hard going.

Consider a page where every single sentence is eighteen words. The average is textbook. The longest is unremarkable. And it is exhausting to read, because eighteen words arrive, then eighteen more, then eighteen more, with no variation in pace at all. Nothing in a conventional readability report catches that, because nothing in a conventional readability report looks at the sentences in the order you wrote them.

That is the view this tool adds. One bar per sentence, left to right, in document order. Good writing has a visible shape: peaks where an idea needs room, troughs where a short sentence lands the point. Bad writing is a flat line, or a wall of tall bars with nowhere to breathe.

What it reports

• The rhythm chart. Sentence lengths in order, coloured by band. The shape of your page at a glance.
• Rhythm as a figure. The spread of your lengths, reported as monotonous, steady or varied. It is the standard deviation of your sentence lengths, which is a dry way of saying: how far a typical sentence sits from your average.
• Runs of long sentences. One long sentence is survivable. Three in a row is where readers leave. Every stretch of three or more is found and located by sentence number.
• Paragraphs with no pause. A paragraph of three or more sentences where not one is under twenty words gives a reader nowhere to rest.
• Every sentence, listed. Not just the longest. The whole set, sorted longest first so the rewriting queue is at the top, filterable down to the very long ones, and exportable.
• Your text marked up. The writing shown back to you with long sentences in amber and very long ones in red, so you see the problem in context rather than in a table somewhere else.

The bands, and why these ones

Sentences are grouped as one word, two to six, seven to fifteen, sixteen to twenty-five, twenty-six to thirty-nine, and forty or more. Those are the bands the established analysers use, so the numbers here are comparable with numbers from elsewhere. Anything from twenty-six words is marked long and anything from forty is marked very long.

They are guides, not rules. A forty-five word sentence with clear parallel clauses can read beautifully. A thirty-word sentence stacked with subordinate clauses can be impenetrable. The marks tell you what to reread, not what to delete.

A splitter that survives real copy

Counting sentences sounds trivial until you try it on actual writing. Split naively on full stops and “Dr. Smith wrote the report” becomes two sentences, “revenue rose 3.5%” becomes two, and “the U.S. market” becomes three. On a page with a few names, some figures and an “e.g.” the count drifts far enough to make the averages meaningless.

So before anything is split, the stops that do not end a sentence are masked out: decimals and thousands separators, dotted acronyms and initials, and a list of common abbreviations from Dr and Mrs through to etc, vs, no and i.e. Ellipses are treated as one mark rather than three. Closing quotes and brackets are kept with the sentence they belong to. A sentence ends when a terminator is followed by whitespace and something that starts a new one, or when the text runs out.

The splitter is checked against two dozen cases of exactly this kind, including “Mr. and Mrs. Jones met Prof. Adams”, “it cost 1,250.75 dollars”, “she joined N.A.S.A. in 1998” and “it was Ford vs. Ferrari”.

How to use the report

Work from the top of the sentence table, because it is already in the order that matters. Rewriting the three longest sentences on a page usually does more for readability than any other single edit, and it takes a few minutes.

The standard fix for an overlong sentence is to find the join. Most of them are two complete thoughts held together by an “and”, a “but”, or a comma doing work a full stop should be doing. Cut there and you have two sentences that each say one thing.

Then look at the rhythm chart rather than the averages. If it is flat, the fix is not to shorten anything: it is to make some sentences much shorter and let others run. A three-word sentence after a long one wakes a reader up. If there is a block of tall bars together, break it with a short one rather than trimming all four.

Does any of this affect rankings?

Not directly. Google does not measure your sentences and reward you for keeping them short, and no readability score is a ranking factor. What sentence length affects is whether people stay, whether they reach the part that answers their question, and whether they come back. A page that loses its reader in the third paragraph has a problem that no amount of tag optimisation will fix.

So this is an editing tool that happens to help your search performance, rather than an SEO tool. That distinction is worth keeping, because it stops you optimising a number instead of improving the writing.

Which tool do I want?

• The Word Counter is for while you are drafting: live counts, reading time, a readability score and a quick length mix, all updating as you type.
• This one is the pass you make afterwards, when the draft exists and you are editing it properly.
• The Keyword Frequency Counter answers what you wrote about and how that compares with a competitor, and the Keyword Density Checker audits where your terms land on a published page.
• When the writing is finished, the Blog Title Analyzer, the Meta Description Checker and the SERP Snippet Preview Tool handle how it presents itself in the results.

Is anything stored?

No. Pasted text is split and measured entirely in your browser and never leaves the page. The exception is checking a page by address: a browser is not permitted to fetch another site’s pages directly, so the address is sent to our server, which reads the page and returns the text. Nothing is written to a database or a log either way, and the report exists only in the open tab. Export the CSV first if you want to keep it.