Which to use
“perf” is an adjective and “perm” is a noun - they look or sound alike but fill different roles in a sentence.
- #42,815
- “perf” frequency rank
- #24,863
- “perm” frequency rank
- 67678
- confusion score
Side-by-Side Comparison
| Feature | perf | perm |
|---|---|---|
| Definition | Abbreviation of perforated; when followed by a number, eg, perf 14, this indicates the number of perforations per two centimetres. | Clipping of permanent wave (“hairstyle”). |
Where the eye mixes perf and perm
Muted = shared; highlighted = the visual trap. They share 3 letters in sequence.
Visual trap between perf and perm
These two trip readers on the page rather than in the ear: perf is /pɜː(ɹ)f/ while perm is /pɝm/. Spoken aloud the problem disappears. In writing it persists, because they differ by a single letter - f in “perf” becomes m in “perm”, and the parts of speech differ too (adjective vs noun), which is usually the fastest check. Our composite confusion score for this pair is 67678, derived from the frequency rank of both members and their visual similarity.
perf is recorded at frequency rank #42,815, classified as anadj, pronounced /pɜː(ɹ)f/. perm is at rank #24,863, tagged as anoun, pronounced /pɝm/.
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 67678, this pair ranks #62,260 of 530,003 scored English confusable pairs - among the most confusable pairs.
Orthographic DNA of perf vs perm
Shared letters: epr. Private to "perf": f. Private to "perm": m.
"perf" · 4 letters · shape CVCC · "perm" · 4 letters · shape CVCC
Known mistypes of this pair
Frequently Asked Questions
Can "perf" and "perm" be used interchangeably?
Frequency check: "perf" vs "perm" - which ranks higher?
Useful next steps
Visual near-miss handled. Browse the word pages or a neighbour when the next look-alike shows up.
- Full dictionary entry for "perf" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "perm" - compare definitions side by side with the headword page. Word entry
- This pair ranks #62,260 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "perf" and "perm" also get mixed up with nearby pairs, the highest-scored neighbour is "pecs vs perf". 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 #62,260 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.