Readability Checker: Check Readability with Standard Scoring

Readability Checker

Check readability using standard scoring. Paste text to get instant metrics and indexes.

Words0
Sentences0
Characters0
Syllables0
Avg words/sent0
Avg syll/word0

Readability Indexes

Flesch Reading Ease0
F‑K Grade Level0
Gunning Fog0
SMOG0
Coleman–Liau0
ARI0
Dale–Chall (est.)0
Overall Grade (avg)0
READY

Readability Checker: See How Text Scores Across Standard Indexes Before Publishing

The Readability Checker evaluates text with a range of classic formulas including Flesch Reading Ease, Flesch‑Kincaid Grade Level, Gunning Fog, SMOG, Coleman–Liau, ARI, and a pragmatic Dale–Chall estimate. It also reports words, sentences, characters, syllables, and averages that reveal how the draft flows.

Why Measure Readability

Readability scores offer a shared language for discussing how approachable a piece of writing feels. They help teams align on expectations for audience level and verify that documents fit their intended context. When a grade skews higher than planned, it usually signals longer sentences, denser vocabulary, or multi‑syllabic clusters that slow readers down.

Measuring readability during drafting is more effective than checking at the end. Early signals reveal where to shorten sentences, remove filler, or clarify phrasing before the structure sets. The result is a piece that reads smoothly on the first pass.

What the Tool Calculates

  • Counts: Words, sentences, characters, and estimated syllables.
  • Averages: Words per sentence and syllables per word.
  • Indexes: Flesch Reading Ease, Flesch‑Kincaid Grade, Gunning Fog, SMOG, Coleman–Liau, ARI, and Dale–Chall (estimate).
  • Aggregate: An overall grade computed from grade‑like indexes to give a single comparative signal.

These signals complement each other. Flesch Reading Ease rises as sentences get shorter and words get simpler. Grade levels move in the opposite direction. Together, they triangulate the reading experience from different angles.

How the Formulas Work

The formulas use three main inputs: sentence length, word length, and syllable patterns. Flesch‑Kincaid uses both sentence and syllable averages to estimate grade level. Gunning Fog emphasizes complex words—typically those with three or more syllables—combined with sentence length. SMOG focuses on polysyllables normalized to a fixed sample of sentences.

Coleman–Liau and ARI rely more on characters per word and words per sentence, which can be more stable across texts with unusual syllable patterns. Dale–Chall estimates difficulty from the proportion of uncommon words relative to a base vocabulary, then adjusts the grade when difficult words exceed a threshold.

Interpreting the Numbers

Higher Flesch Reading Ease indicates simpler text, with scores above 60 commonly aligned with general audiences. Grade indexes cluster around the U.S. school grade system, where 8–10 suggests broadly accessible coverage and 12+ indicates more specialized or academic phrasing. The overall grade average provides a single roll‑up, useful for tracking changes across revisions.

Because each formula weighs inputs differently, minor discrepancies between indexes are normal. The most useful way to read them is in concert, not isolation, to see whether a trend appears consistently across measures.

From Draft to Decision

A common workflow begins by pasting a draft and scanning counts for outliers: unusually long sentences, elevated syllables per word, or large character totals relative to word count. If the grade average overshoots the target, writers split long sentences, swap jargon for plain terms, and remove scaffolding phrases that add length without clarity.

After small edits, a fresh analysis shows immediate movement in scores. This tight loop makes it easy to converge on the intended reading level without heavy rewrites or guesswork.

Why an Aggregate Grade Helps

An aggregate average flattens formula‑specific quirks and creates a stable baseline to compare drafts. While no single number can capture every nuance, a blended grade is a practical compass when evaluating multiple pieces or tracking a document over time. It helps editors decide when a draft is close enough to move forward.

The aggregate is especially handy for content programs with defined audience bands, where editors monitor ranges rather than aiming for a single fixed value.

Syllables, Complex Words, and Flow

Syllable estimates reveal how word choice influences cadence. A high concentration of polysyllables can slow reading even when sentences are not long. Simple substitutions often reduce syllables without losing precision. Tracking average syllables per word alongside sentence length gives a fuller picture of how a draft feels in motion.

Complex word counts also show when specialized terms cluster, which can be necessary in technical contexts but may warrant added definitions or examples for general readers.

Local Analysis for Speed and Privacy

Running readability checks in the browser keeps drafts private while delivering instant feedback. There is no waiting for network calls or external services, and sensitive material stays on‑device. This makes the checker suitable for early copies, confidential briefs, and pre‑launch documentation where control matters.

Local processing also scales smoothly from short notes to long‑form pieces. The interface remains responsive and supports iterative editing without leaving the page.

Using the Checker in Team Workflows

Teams incorporate the checker during outline reviews, first drafts, and pre‑publish passes. Writers verify that their sections meet the intended reading level, while editors scan aggregate grades to maintain consistency across a collection. Because metrics are shared and repeatable, feedback stays focused on specific changes that move the numbers in the right direction.

In documentation and support content, stable readability ranges help reduce misinterpretation and support quicker task completion for readers under time pressure.

Summary

The Readability Checker distills sentence length, word complexity, and character density into interpretable scores. By combining classic formulas with clear counts and an aggregated grade, it guides drafting toward the intended audience level without slowing the writing process. The result is copy that reads smoothly, respects constraints, and supports confident publication.