LvsluxWhich spelling fits?

Quick tell: L is a symbol, lux is a noun, so they fill different roles in a sentence.

Which to use

“L” is a symbol and “lux” is a noun - they look or sound alike but fill different roles in a sentence.

#5
“L” frequency rank
#18,246
“lux” frequency rank
18251
confusion score

Side-by-Side Comparison

Feature L lux
Definition Ancien symbole chimique du lithium (aujourd’hui Li). Unité de mesure d’éclairement lumineux du Système international, définie comme lumen par mètre carré, dont le symbole est lx.

Letter map: L vs lux

Shared letters muted; letters that set L and lux apart highlighted. Shared run: 1.

1 ch
L
3 ch
lux

Part-of-speech tell for L / lux

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: L is asymbol and luxanoun. On the page they differ by 2 extra letter(s) - “L” sits inside “lux”. Our composite confusion score for this pair is 18251, derived from the frequency rank of both members and their visual similarity.

L is recorded at frequency rank #5, classified as asymbol. lux is at rank #18,246, tagged as anoun, pronounced \lyks\.

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 18251, this pair ranks #379,269 of 440,172 scored French confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of L vs lux

Shared letters: l. Private to "L": -. Private to "lux": ux.

"L" · 1 letters · shape C  ·  "lux" · 3 letters · shape CVC

Frequently Asked Questions

Is swapping "L" for "lux" ever safe?
No - they are not even the same part of speech. "L" is a symbol and "lux" a noun, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "L" or "lux"?
"L" is the more common of the two: it sits at frequency rank #5 in our French list, against #18,246 for "lux". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

What to do next

Done with this confusable. These links stay specific to "L" and "lux".

  • Full dictionary entry for "L" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "lux" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #379,269 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
  • "L" and "lux" also get mixed up with nearby pairs, the highest-scored neighbour is "lep vs lux". Nearby pair

Confusion rank #379,269 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.

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

Source: FrequencyWords open word-frequency list