Which to use
“ko” and “koi” are a confusable English pair: similar on the page, but distinct in meaning, check the gloss before you choose.
- #10,717
- “ko” frequency rank
- #26,483
- “koi” frequency rank
- 37200
- confusion score
Side-by-Side Comparison
| Feature | ko | koi |
|---|---|---|
| Definition | A local shape to which the ko rule applies; a ko shape. | Ornamental domesticated varieties of the Amur carp (Cyprinus rubrofuscus), of Japan and eastern Asia with red-gold or white coloring. |
Where the eye mixes ko and koi
Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.
Why the eye confuses ko with koi
A purely visual mix-up. ko (/ˈkəʊ/) and koi (/kɔɪ/) are said differently, so reading them aloud is the quickest way to catch the wrong one. On the page they stay close: they differ by 1 extra letter(s) - “ko” sits inside “koi”. Our composite confusion score for this pair is 37200, derived from the frequency rank of both members and their visual similarity.
ko is recorded at frequency rank #10,717, classified as anoun, pronounced /ˈkəʊ/. koi is at rank #26,483, tagged as anoun, pronounced /kɔɪ/.
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 37200, this pair ranks #296,555 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of ko vs koi
Shared letters: ko. Private to "ko": -. Private to "koi": i.
"ko" · 2 letters · shape CV · "koi" · 3 letters · shape CVV
Frequently Asked Questions
Is swapping "ko" for "koi" ever safe?
Which is more common, "ko" or "koi"?
Useful next steps
Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.
- Full dictionary entry for "ko" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "koi" - compare definitions side by side with the headword page. Word entry
- This pair ranks #296,555 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "ko" and "koi" also get mixed up with nearby pairs, the highest-scored neighbour is "koi vs Kop". Nearby pair
Confusion rank #296,555 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.