ICOvsIJWhich spelling fits?

Quick tell: ICO is a noun, IJ is a name, so they fill different roles in a sentence.

Which to use

“ICO” is a noun and “IJ” is a name - they look or sound alike but fill different roles in a sentence.

#23,564
“ICO” frequency rank
#46,535
“IJ” frequency rank
70099
confusion score

Side-by-Side Comparison

Feature ICO IJ
Definition Initialism of initial coin offering. A lake (formerly a bay) adjoining the city of Amsterdam, Netherlands.

Letter map: ICO vs IJ

Shared letters muted; letters that set ICO and IJ apart highlighted. Shared run: 1.

3 ch
ICO
2 ch
IJ

Grammar separator: ICO vs IJ

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: ICO is anoun and IJaname. On the page they differ by 1 letter(s) in length. Our composite confusion score for this pair is 70099, derived from the frequency rank of both members and their visual similarity.

ICO is recorded at frequency rank #23,564, classified as anoun. IJ is at rank #46,535, tagged as aname, pronounced /eɪ/.

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 70099, this pair ranks #51,935 of 530,003 scored English confusable pairs - among the most confusable pairs.

Orthographic DNA of ICO vs IJ

Shared letters: i. Private to "ICO": co. Private to "IJ": j.

"ICO" · 3 letters · shape VCV  ·  "IJ" · 2 letters · shape VC

Frequently Asked Questions

Is swapping "ICO" for "IJ" ever safe?
No - they are not even the same part of speech. "ICO" is a noun and "IJ" a name, so a sentence built for one is usually ungrammatical with the other.
In ordinary English text, does "ICO" or "IJ" show up more?
"ICO" is the more common of the two: it sits at frequency rank #23,564 in our English list, against #46,535 for "IJ". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Useful next steps

Done with this confusable. These links stay specific to "ICO" and "IJ".

  • Full dictionary entry for "ICO" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "IJ" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #51,935 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "ICO" and "IJ" also get mixed up with nearby pairs, the highest-scored neighbour is "IJ vs ith". Nearby pair

Confusion rank #51,935 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list