Lipogram Checker

How to Use the Lipogram Checker

1. Paste or type your text into the input area. Anything from a single sentence to a 50,000-character chapter works.
2. Type the letters you want the text to avoid. Use spaces, commas, or jammed input (eta, e t a, e,t,a).
3. Optionally click letters on the A-Z dial to toggle them as forbidden, or pick a famous-lipogram preset.
4. Press Check Lipogram. The report shows pass/fail, highlighted text, a per-letter heatmap, a list of violating words, and a difficulty rating.

What Is a Lipogram?

A lipogram (from Greek leipogrammatos, "leaving out a letter") is a piece of writing that intentionally avoids one or more letters of the alphabet. The constraint forces the writer to find synonyms, restructure sentences, and reach for vocabulary they would not normally use. It is one of the oldest and most rewarding forms of constrained writing.

Famous Lipograms

Lipogram vs Univocalic vs Pangram

• Lipogram — forbids one or more letters.
• Univocalic — a stricter lipogram that allows only one vowel. The Eunoia presets implement this by forbidding the other four vowels.
• Pangram — the opposite: a sentence that uses every letter of the alphabet at least once. "The quick brown fox jumps over the lazy dog" is the classic example.

What the Difficulty Meter Means

English letters are not used equally. The letter E is roughly 12.7% of all letters in typical English text; T is about 9.1%; A about 8.2%. The difficulty meter sums the English-frequency percentages of every forbidden letter and labels the constraint:

• Trivial — under 5%. Forbidding Q, X, Z barely affects normal writing.
• Easy — 5–15%. A single common letter like S or H falls here.
• Moderate — 15–30%. Avoiding E alone (12.7%) sits at the edge of this band; add T or A and you cross it.
• Hard — 30–50%. Multi-letter constraints reach this level quickly.
• Extreme — over 50%. Most univocalic constraints (only one vowel allowed) land here because the other four vowels together account for the majority of vowel mass.

Use Cases

• Verify a lipogram poem or short story before submitting it to a constrained-writing contest.
• Practice univocalic chapters in the style of Christian Bök's Eunoia.
• Teach creative-writing students about the trade-off between meaning and constraint.
• Test text generation models or game-design constraints that require specific letters to be absent.
• Quickly find which sentences in a draft contain a particular letter you are trying to phase out.

FAQ

What is a lipogram?

A lipogram is a piece of writing that intentionally avoids one or more letters of the alphabet. The most famous example is Ernest Vincent Wright's 1939 novel Gadsby, which was written without using the letter E.

What is the difference between a lipogram and a univocalic?

A lipogram forbids specific letters. A univocalic permits only one vowel; the other four vowels are forbidden. Christian Bök's book Eunoia contains five univocalic chapters, one for each vowel.

Does the checker care about case?

By default no. Forbidding E also flags every uppercase E. Turn on case-sensitive mode if you want to treat E and e as separate letters.

How are accented letters such as é treated?

By default accented letters are normalized to their base form before checking, so é matches e and ñ matches n. Turn off Ignore diacritics if you want é and e to be treated as different letters.

What does the difficulty meter show?

It adds up the typical English usage frequencies of every forbidden letter and labels the result Trivial, Easy, Moderate, Hard, or Extreme. Avoiding E alone scores 12.7 percent because roughly one in every eight English letters is an E.

What counts as a word violation?

A word is flagged when it contains at least one forbidden letter. The compliance percentage shows the share of words that are completely free of forbidden letters.