instávelvsinviávelWhat's the difference?

Which to use

“instável” and “inviável” are a confusable Portuguese pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#9,871
“instável” frequency rank
#20,341
“inviável” frequency rank
30212
confusion score

Side-by-Side Comparison

Feature instável inviável
Definition não estável por onde não se pode passar; intransponível

Where the eye mixes instável and inviável

Muted = shared; highlighted = the visual trap. They share 6 letters in sequence. instável (VCCCVCVC) and inviável (VCCVVCVC) run the same length but a different consonant-vowel pattern - the shape difference is usually the fastest tell.

8 ch
instável
8 ch
inviável

Look-alike desk: instável vs inviável

A purely visual mix-up. instável (/ĩʃ.ˈta.vɛɫ/) and inviável (/ĩ.ˈvja.vɛɫ/) are said differently, so reading them aloud is the quickest way to catch the wrong one. On the page they stay close: they share most of their letters but differ in 2 positions. Our composite confusion score for this pair is 30212, derived from the frequency rank of both members and their visual similarity.

instável is recorded at frequency rank #9,871, classified as anadj, pronounced /ĩʃ.ˈta.vɛɫ/. inviável is at rank #20,341, tagged as anadj, pronounced /ĩ.ˈvja.vɛɫ/.

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 30212, this pair ranks #38,218 of 75,631 scored Portuguese confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of instável vs inviável

Shared letters: eilnvá. Private to "instável": st. Private to "inviável": -.

"instável" · 8 letters · shape VCCCVCVC  ·  "inviável" · 8 letters · shape VCCVVCVC

Frequently Asked Questions

Is swapping "instável" for "inviável" ever safe?
No. They are said differently (/ĩʃ.ˈta.vɛɫ/ versus /ĩ.ˈvja.vɛɫ/) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.
Frequency check: "instável" vs "inviável" - which ranks higher?
"instável" is the more common of the two: it sits at frequency rank #9,871 in our Portuguese list, against #20,341 for "inviável". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

What to do next

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

  • Full dictionary entry for "instável" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "inviável" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #38,218 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
  • "instável" and "inviável" also get mixed up with nearby pairs, the highest-scored neighbour is "inegável vs inviável". Nearby pair

Confusion rank #38,218 of 75,631 scored Portuguese pairs, corpus vintage 2026-09-03, not spelling advice.

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

Source: FrequencyWords open word-frequency list