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Iambic Pentameter
Checker

Paste any line and instantly check syllable count, da-DUM stress pattern, and whether it follows iambic pentameter. Works for sonnets, plays, and any verse.

Validates 10-syllable iambic pentameter
Shows da-DUM stress pattern per word
Check single lines or full sonnets (14 lines)
daDUM · daDUM · daDUM · daDUM · daDUM = 10 syllables
Iambic Pentameter Checker

Check your meter

Try an example:

Type a line above to check its meter
Meter explained

What is iambic pentameter?

The heartbeat of English poetry — 10 syllables, alternating stress, five feet.

An iamb is a pair of syllables: unstressed followed by stressed — da-DUM. Pentameter means five feet. Together: five da-DUM pairs = 10 syllables per line.

  • Shakespeare used it everywhere — sonnets, plays, speeches. "To BE or NOT to BE, that IS the QUES-tion" — 10 syllables, 5 iambs.
  • Feminine endings are OK — 11 syllables with an extra unstressed syllable at the end. Shakespeare used them frequently for a softer, more natural sound.
  • Substitutions happen — poets sometimes swap a trochee (DUM-da) for the first iamb. This is called a "trochaic substitution" and is completely valid.
  • Elision compresses syllables — "over" can become "o'er" (1 syllable), "the evening" can become "th'evening". Poets do this to fit the meter.
Shakespeare — Sonnet 18
"Shall I compare thee to a summer's day?"
ShallI com-pare theeto asum- mer'sday
10 syllables ✓ Perfect iambic pentameter
"Thou art more lovely and more temperate."
Thouart morelove- lyand moretem- pe-rate
10 syllables ✓ Perfect iambic pentameter
"To be or not to be, that is the question."
toBE orNOT toBE thatIS theQUES tion
11 syllables — feminine ending (valid)
FAQ

Frequently asked questions

Quick answers about iambic pentameter and this checker.

Iambic pentameter is a poetic meter with 10 syllables per line: five pairs (feet) of unstressed-stressed syllables — da-DUM da-DUM da-DUM da-DUM da-DUM. It's the most common meter in English poetry, used by Shakespeare, Milton, Keats, and many others.
Traditional iambic pentameter has 10 syllables. However, poets often use 11 syllables with a "feminine ending" — an extra unstressed syllable at the end of the line. Shakespeare used this constantly. This tool accepts both 10 and 11 syllables as valid.
A foot is a basic unit of poetic meter — a fixed pattern of stressed and unstressed syllables. An iamb is one foot = da-DUM. Pentameter means 5 feet. So iambic pentameter = 5 iambs = da-DUM da-DUM da-DUM da-DUM da-DUM = 10 syllables.
Yes! Switch to "Full poem / Sonnet" mode and paste all 14 lines. The tool checks each line separately and shows a summary: how many lines pass (10-11 syllables), how many are close (9 or 12), and how many need fixing.
A trochee is the reverse of an iamb — DUM-da instead of da-DUM. Poets sometimes swap the first iamb in a line with a trochee for emphasis or variety. "LOVE-ly" at the start of a line instead of "love-LY" is a common trochaic substitution. It is completely valid and not an error.
No. Everything runs locally in your browser. Your lines and poems never leave your device — completely private, no server, no logging.