Syllable Counter — accurate syllables, ratio & readability scores
Paste any text and instantly see syllables per word, the syllable-to-word ratio, a distribution histogram and six readability scores (Flesch, Flesch-Kincaid, SMOG, Gunning Fog, Coleman-Liau, ARI). Powered by Titus Wormer's syllable library with an optional Strict mode that loads the full Carnegie Mellon Pronouncing Dictionary for true 100% accuracy on ~134k English words.
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Top 10 words by syllable count will appear here.
Write your poem above
Each line is checked against the chosen pattern.
What you can use the syllable counter for
From haiku verification to academic readability — six in-browser scores tell you exactly how dense your text reads.
Haiku & poetry
Verify 5-7-5, tanka, cinquain or any custom syllable pattern line by line.
Readability scoring
Flesch, Flesch-Kincaid, SMOG, Gunning Fog, Coleman-Liau, ARI — the six standard scores side by side.
Education & ESL
Pick texts at the right grade level. SMOG estimates years of education needed.
Copywriting
Catch long polysyllabic words that hurt scannability and replace them with shorter alternatives.
Songwriting & lyrics
Fit syllables to a melody. The per-word view shows exactly where the stress lands.
Linguistics & NLP research
Compare syllable.js heuristics against the CMU dictionary on any corpus you paste in.
How to count syllables online (3 steps)
Paste or type your text
Drop any English text into the editor — a word, a haiku, a paragraph, an article. TXT, DOCX and PDF upload work too.
Pick Fast or Strict engine
Fast uses Titus Wormer's syllable library (CMU-derived dictionary + heuristics, ~95–98% accurate). Strict downloads the full CMU dictionary (~1.5 MB, one-time) for 100% accuracy on the ~134k English words it covers.
Read the report
Per-word syllables, ratios, distribution histogram, top-10 most complex words, six readability scores, and a poem helper that checks any syllable pattern. Export CSV / JSON / plain text.
Frequently asked questions
The default Fast engine uses Titus Wormer's syllable.js — a CMU-derived dictionary of common words plus a tuned heuristic fallback, reaching about 95–98% accuracy on regular English. The Strict engine loads the full Carnegie Mellon Pronouncing Dictionary (~134k words) and counts vowel phonemes for a true 100% syllable count on every word it covers. Words not in CMU automatically fall back to the heuristic.
Yes. 100% free, ad-free, no signup, no daily limits.
Six scores: Flesch Reading Ease (0–100, higher is easier), Flesch-Kincaid Grade Level (US school grade), SMOG Index (years of education needed), Gunning Fog Index (years of formal education), Coleman-Liau Index (grade level), and the Automated Readability Index (ARI) (grade level). All use the same syllable-aware text analysis under the hood.
Yes. The poem helper at the bottom of the page checks each line against your chosen target — haiku 5-7-5, tanka 5-7-5-7-7, cinquain 2-4-6-8-2, or any custom pattern like 4-6-4-6-4.
After the first visit, yes. The syllable library and the optional CMU dictionary are cached by the shared HCODX service worker, so subsequent visits load instantly and work without an internet connection.
Yes. Upload TXT, DOCX (via Mammoth) or PDF (via PDF.js) — extraction runs entirely in your browser, then the syllable counter treats it like any other text input.
In readability statistics, a polysyllabic word has three or more syllables. The SMOG index, for example, counts only polysyllables when estimating the years of education needed to understand a text.
The syllable.js library and CMU dictionary are English-specific. For other languages the count falls back to a vowel-group heuristic — roughly accurate for Latin-script languages but not as precise as the English engine.
About this syllable counter
HCODX's Syllable Counter is a free, ad-free, no-signup tool for counting syllables and computing readability scores — directly in your browser.
How the syllable count is computed
- Fast engine — uses syllable.js by Titus Wormer. The library ships a curated subset of the CMU Pronouncing Dictionary for common words plus a tuned heuristic for everything else (vowel groups, common suffixes like
-le, silent-ehandling, double-vowel splits, etc.). It's the engine used by every JS readability library worth using and benchmarks at 95–98% accuracy on standard English. - Strict engine — loads the full Carnegie Mellon Pronouncing Dictionary (~134k words) and counts vowel phonemes (those with stress markers
0,1,2) — the canonical definition of a syllable. Words not in CMU fall back to syllable.js so the tool never refuses to count.
Readability formulas
- Flesch Reading Ease —
206.835 − 1.015·(words/sentences) − 84.6·(syllables/words). Higher is easier; 60–70 ≈ plain English. - Flesch-Kincaid Grade —
0.39·(words/sentences) + 11.8·(syllables/words) − 15.59. US school grade level. - SMOG Index —
1.0430·√(polysyllables·30/sentences) + 3.1291. Years of education to understand the text. - Gunning Fog —
0.4·((words/sentences) + 100·(complex/words)). Years of formal education. - Coleman-Liau —
0.0588·L − 0.296·S − 15.8where L = letters per 100 words, S = sentences per 100 words. - Automated Readability Index (ARI) —
4.71·(chars/words) + 0.5·(words/sentences) − 21.43. Grade level.
Privacy
- Your text never leaves the browser. Everything runs locally.
- The syllable library and CMU dictionary are fetched from jsDelivr and cached by the shared
/tools/cache-worker.jsservice worker, so subsequent visits work offline.