luxvsluzTell them apart

Which to use

“lux” and “luz” are a confusable Spanish pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#23,482
“lux” frequency rank
#469
“luz” frequency rank
23951
confusion score

Side-by-Side Comparison

Feature lux luz
Definition Unidad derivada del Sistema Internacional de Unidades para la iluminancia o nivel de iluminación, equivalente a un lumen por metro cuadrado. Radiación electromagnética visible al ojo humano.

Where the eye mixes lux and luz

Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.

3 ch
lux
3 ch
luz

Visual trap between lux and luz

A purely visual mix-up. lux ([ˈluks]) and luz ([ˈlus]) 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 a single letter - x in “lux” becomes z in “luz”. Our composite confusion score for this pair is 23951, derived from the frequency rank of both members and their visual similarity.

lux is recorded at frequency rank #23,482, classified as anoun, pronounced [ˈluks]. luz is at rank #469, tagged as anoun, pronounced [ˈlus].

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 23951, this pair ranks #243,409 of 323,831 scored Spanish confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of lux vs luz

Shared letters: lu. Private to "lux": x. Private to "luz": z.

"lux" · 3 letters · shape CVC  ·  "luz" · 3 letters · shape CVC

Frequently Asked Questions

Do "lux" and "luz" mean the same thing in a sentence?
No. They are said differently ([ˈluks] versus [ˈlus]) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.
Frequency check: "lux" vs "luz" - which ranks higher?
"luz" is the more common of the two: it sits at frequency rank #469 in our Spanish list, against #23,482 for "lux". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

After this comparison

Visual near-miss handled. Browse the word pages or a neighbour when the next look-alike shows up.

  • Full dictionary entry for "lux" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "luz" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #243,409 of 323,831 scored Spanish confusable pairs in this corpus vintage. Corpus statistics
  • "lux" and "luz" also get mixed up with nearby pairs, the highest-scored neighbour is "lac vs lux". Nearby pair

Confusion rank #243,409 of 323,831 scored Spanish pairs, corpus vintage 2026-09-03, not spelling advice.

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

Source: FrequencyWords open word-frequency list