Which to use
“io” and “iron” are a confusable English pair: similar on the page, but distinct in meaning, check the gloss before you choose.
- #16,946
- “io” frequency rank
- #1,866
- “iron” frequency rank
- 18812
- confusion score
Side-by-Side Comparison
| Feature | io | iron |
|---|---|---|
| Definition | A type of moth, the io moth. | A common, inexpensive metal, silvery grey when untarnished, that rusts, is attracted by magnets, and is used in making steel: a chemical element having atomic number 26 and symbol Fe. |
Where the eye mixes io and iron
Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.
Why the eye confuses io with iron
A purely visual mix-up. io (/ˈaɪəʊ/) and iron (/æːn/) 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 2 letter(s) in length. Our composite confusion score for this pair is 18812, derived from the frequency rank of both members and their visual similarity.
io is recorded at frequency rank #16,946, classified as anoun, pronounced /ˈaɪəʊ/. iron is at rank #1,866, tagged as anoun, pronounced /æːn/.
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 18812, this pair ranks #442,399 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.
Orthographic DNA of io vs iron
Shared letters: io. Private to "io": -. Private to "iron": nr.
"io" · 2 letters · shape VV · "iron" · 4 letters · shape VCVC
Known mistypes of this pair
- iron ← iorn · irno · ironn · irron · rion
Frequently Asked Questions
Can "io" and "iron" be used interchangeably?
Which is more common, "io" or "iron"?
After this comparison
Eye-level mix-up between "io" and "iron" is sorted above. Next: full entries or other pairs that share a letter shape.
- Full dictionary entry for "io" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "iron" - compare definitions side by side with the headword page. Word entry
- This pair ranks #442,399 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "io" and "iron" also get mixed up with nearby pairs, the highest-scored neighbour is "io vs ith". 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 #442,399 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.