Which to use
“flatten” is a verb and “flatter” is an adjective - they look or sound alike but fill different roles in a sentence.
- #29,657
- “flatten” frequency rank
- #20,359
- “flatter” frequency rank
- 50016
- confusion score
Side-by-Side Comparison
| Feature | flatten | flatter |
|---|---|---|
| Definition | To make something flat or flatter. | comparative form of flat: more flat |
Where the eye mixes flatten and flatter
Muted = shared; highlighted = the visual trap. They share 6 letters in sequence.
Look-alike desk: flatten vs flatter
These two trip readers on the page rather than in the ear: flatten is /ˈflæ.tən/ while flatter is /ˈflætɚ/. Spoken aloud the problem disappears. In writing it persists, because they differ by a single letter - n in “flatten” becomes r in “flatter”, and the parts of speech differ too (verb vs adjective), which is usually the fastest check. Our composite confusion score for this pair is 50016, derived from the frequency rank of both members and their visual similarity.
flatten is recorded at frequency rank #29,657, classified as averb, pronounced /ˈflæ.tən/. flatter is at rank #20,359, tagged as anadj, pronounced /ˈflætɚ/.
Glosses for this pair are partially populated in our dataset, but the full side-by-side definitions above should still guide you to the right choice.
With a confusion score of 50016, this pair ranks #178,141 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of flatten vs flatter
Shared letters: aeflt. Private to "flatten": n. Private to "flatter": r.
"flatten" · 7 letters · shape CCVCCVC · "flatter" · 7 letters · shape CCVCCVC
Known mistypes of this pair
Frequently Asked Questions
Can "flatten" and "flatter" be used interchangeably?
Which is more common, "flatten" or "flatter"?
Useful next steps
Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.
- Full dictionary entry for "flatten" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "flatter" - compare definitions side by side with the headword page. Word entry
- This pair ranks #178,141 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "flatten" and "flatter" also get mixed up with nearby pairs, the highest-scored neighbour is "flatbed vs flatten". Nearby pair
- Recorded mistypes exist for at least one side of this pair, useful when a spell-checker or OCR lands on the wrong form. See mistypes
Confusion rank #178,141 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.