IAS vs io, What's the Difference?

Which to use

“IAS” and “io” are a confusable English pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#31,214
“IAS” frequency rank: #16,946
“io” frequency rank: 48160
confusion score

Side-by-Side Comparison

Feature	IAS	io
Definition	Initialism of indicated airspeed.	A type of moth, the io moth.

Letter map: IAS vs io

Shared letters muted; letters that set IAS and io apart highlighted. Shared run: 1. IAS runs 3 letters (VVC) against io's 2 (VV) - the length gap alone is often enough to separate them once you know to check it.

3 ch

IAS

2 ch

Corpus notes: IAS and io

IAS and io are indexed as a confusable English pair. We have no recorded pronunciation or part of speech for both members, so the spelling overlap is what we can show you: they differ by 1 letter(s) in length. Our composite confusion score for this pair is 48160, derived from the frequency rank of both members and their visual similarity.

IAS is recorded at frequency rank #31,214, classified as anoun. io is at rank #16,946, tagged as anoun, pronounced /ˈaɪəʊ/.

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 48160, this pair ranks #195,692 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of IAS vs io

Shared letters: i. Private to "IAS": as. Private to "io": o.

"IAS" · 3 letters · shape VVC · "io" · 2 letters · shape VV

Frequently Asked Questions

Do "IAS" and "io" mean the same thing in a sentence?

No. They differ by 1 letter(s) in length, but the dictionary glosses above give them different meanings, so swapping one for the other changes what the sentence says.

Frequency check: "IAS" vs "io" - which ranks higher?

"io" is the more common of the two: it sits at frequency rank #16,946 in our English list, against #31,214 for "IAS". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Useful next steps

You've compared "IAS" and "io". Here's where to go from here.

Full dictionary entry for "IAS" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "io" - compare definitions side by side with the headword page. Word entry
This pair ranks #195,692 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
"IAS" and "io" also get mixed up with nearby pairs, the highest-scored neighbour is "IAS vs Ilan". Nearby pair

Confusion rank #195,692 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.