BYTETOOLS

Sentence Length Analyzer

Analyze sentence lengths: average, median, longest, shortest and variation, with long sentences flagged in color. Free and 100% in-browser.

0
Sentences
—
Average words
—
Median words
—
Shortest / longest
—
Std deviation
0
Over 25 words

Red = over your threshold, amber = within 80% of it. Varying sentence length matters as much as the average — a healthy mix of short and long sentences keeps prose readable.

What is the Sentence Length Analyzer?

Sentence Length Analyzer breaks your text into sentences and measures each one, reporting the average, median, shortest and longest lengths plus the standard deviation — a direct read-out of how much your sentence rhythm varies.

  • Average, median, shortest and longest sentence lengths
  • Standard deviation shows rhythm and variety
  • Configurable threshold with red/amber flagging
  • Per-sentence word-count badges
  • Abbreviation-aware sentence splitting (Dr., e.g., U.S.)
  • Runs fully offline in your browser

How to use the Sentence Length Analyzer

  1. 1

    Paste your text into the input box.

  2. 2

    Set the word threshold above which sentences should be flagged (default 25).

  3. 3

    Review the average, median and variation stats.

  4. 4

    Fix the red (over-threshold) and amber (near-threshold) sentences in the list.

About the Sentence Length Analyzer

Sentence Length Analyzer breaks your text into sentences and measures each one, reporting the average, median, shortest and longest lengths plus the standard deviation — a direct read-out of how much your sentence rhythm varies. Every sentence is listed with its word count, color-coded against a threshold you control.

Long sentences are the fastest way to lose readers: most style guides suggest keeping the average near 15–20 words and flagging anything over 25. But monotony matters too — if your standard deviation is tiny, every sentence is the same length and the prose drones. This tool exposes both problems at a glance.

Analysis is 100% local to your browser; your draft is never uploaded, and the tool works offline.

Frequently asked questions

What is a good average sentence length?

Most modern style guidance puts readable prose at 15–20 words on average, with hard-hitting copy often lower. Above 25 words per sentence, comprehension measurably drops for general audiences. Technical and legal writing runs longer by nature.

Why does sentence variety matter, not just the average?

A text where every sentence is 15 words reads as monotone even though the average looks perfect. The standard deviation here measures that spread — good prose mixes short punchy sentences with longer flowing ones, which shows up as a healthy deviation of roughly 5–10 words.

How does the tool detect sentence boundaries?

It splits on periods, question marks and exclamation points, with a guard list of common abbreviations (Mr., Dr., e.g., U.S.) and single-letter initials so those periods don't create false sentence breaks. Unusual formatting can still fool it occasionally.

What do the red and amber colors mean?

Red sentences exceed your threshold; amber ones are within 80% of it — close enough to watch. Everything else is left neutral. Adjust the threshold to your style guide and the colors update instantly.

Is my writing uploaded to a server?

No. The entire analysis runs in your browser, so unpublished drafts stay private and the tool works offline.

Related tools