Text analyzer — instant readability, tone & SEO insights

What does a text analyzer measure?

A text analyzer turns words into numbers. Where you might intuitively feel that a sentence is “too long” or a paragraph reads “too dense,” an analyzer gives you specific scores: an average grade level, a Flesch Reading Ease number, a syllable-per-word ratio. These let you make objective edits instead of guessing.

GrammarBot’s analyzer computes three families of metrics:

• Readability formulas — five industry-standard scores (Flesch Reading Ease, Flesch-Kincaid Grade Level, SMOG, Coleman-Liau, Automated Readability Index) plus a Dale-Chall approximation. Each surfaces a different aspect: Flesch weighs sentence length and syllables, SMOG focuses on polysyllabic words, Coleman-Liau uses character count instead of syllables (more reliable on technical text).
• Statistics — word count, sentence count, paragraph count, syllables, complex words (3+ syllables), unique words, lexical diversity, average words per sentence, longest sentence, and estimated reading and speaking time.
• Tone & SEO — formality classification (formal / neutral / casual), basic sentiment, and a keyword density breakdown for content marketers.

When should you use a text analyzer?

Before publishing. Bloggers, copywriters, and content marketers use text analyzers as a final pre-publish check. If your target audience is grade-7 readers but your draft scores at grade-13, you have a problem before you have a reader.

During iteration.Re-run the analyzer after each edit. Did breaking that 40-word sentence into two improve your score? Did swapping “utilize” for “use” nudge your Flesch Ease up by three points? These small wins compound.

For audience matching.A B2B whitepaper aimed at CFOs should read differently from a SaaS landing page or a YA novel. Use the analyzer to confirm the text matches the audience’s expected complexity, not the writer’s default voice.

For SEO benchmarking. Top-ranking pages for a given query tend to cluster around specific readability and length norms. Run them through the analyzer, average the scores, and target the same range.

How readability formulas work (the short version)

All five formulas approximate the same thing — how hard your text is to read — using different proxies for complexity. The simplest is Flesch Reading Ease:

206.835 − 1.015 × (words / sentences) − 84.6 × (syllables / words)

Long sentences hurt your score. Long words hurt your score. That’s it. The output is a number from 0 (very difficult) to 100 (very easy). Most consumer-facing writing aims for 60–70. Technical documentation often lives at 30–50.

Flesch-Kincaid Grade Level uses the same inputs but outputs a US grade level — 8.5 means the average 8th grader can read this comfortably. SMOG swaps syllable counting for polysyllabic word counting (more reliable on shorter texts). Coleman-Liau uses character count instead of syllables (better for software and technical content where syllable heuristics fail). ARI is similar to Coleman-Liau but tuned for typewritten text.

Practical tips for improving any text

• Aim for an average of 15-20 words per sentence. Vary the rhythm, but the average matters.
• Replace polysyllabic words with shorter ones when meaning isn’t lost. “Utilize” → “use.” “Commence” → “start.” “Subsequently” → “then.”
• Break sentences over 25 words. Almost every long sentence can become two clearer ones.
• Cut adverbs and intensifiers. “Really very actually” earns nothing.
• Watch lexical diversity. Below 40% suggests repetitive vocabulary; above 70% can feel showy. Most professional writing lands at 50–65%.

Privacy and how this tool works

GrammarBot’s text analyzer runs entirely in your browser. The JavaScript code computes every metric locally — your text is never sent to a server. There’s no account requirement, no character limit, no rate limiting, and no upsell. We track anonymous usage analytics (page views, button clicks) but never the content of your text.