A4 vs aux, What's the Difference?

Which to use

“A4” is a symbol and “aux” is an article - they look or sound alike but fill different roles in a sentence.

#18,920
“A4” frequency rank: #58
“aux” frequency rank: 18978
confusion score

Side-by-Side Comparison

Feature	A4	aux
Definition	Format de papier de 210 mm × 297 mm.	Contraction obligatoire de la préposition à et de l'article défini les.

Letter map: A4 vs aux

Shared letters muted; letters that set A4 and aux apart highlighted. Shared run: 1.

2 ch

3 ch

aux

Grammar separator: A4 vs aux

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: A4 is asymbol and auxanarticle. On the page they differ by 1 letter(s) in length. Our composite confusion score for this pair is 18978, derived from the frequency rank of both members and their visual similarity.

A4 is recorded at frequency rank #18,920, classified as asymbol. aux is at rank #58, tagged as anarticle, pronounced \o\.

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 18978, this pair ranks #375,634 of 440,172 scored French confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of A4 vs aux

Shared letters: a. Private to "A4": -. Private to "aux": ux.

"A4" · 1 letters · shape V · "aux" · 3 letters · shape VVC

Frequently Asked Questions

Is swapping "A4" for "aux" ever safe?

No - they are not even the same part of speech. "A4" is a symbol and "aux" an article, so a sentence built for one is usually ungrammatical with the other.

In ordinary French text, does "A4" or "aux" show up more?

"aux" is the more common of the two: it sits at frequency rank #58 in our French list, against #18,920 for "A4". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

After this comparison

Done with this confusable. These links stay specific to "A4" and "aux".

Full dictionary entry for "A4" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "aux" - compare definitions side by side with the headword page. Word entry
This pair ranks #375,634 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
"A4" and "aux" also get mixed up with nearby pairs, the highest-scored neighbour is "A4 vs aur". Nearby pair

Confusion rank #375,634 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.