impassablevsimpossibleTell them apart

Which to use

“impassable” and “impossible” are a confusable English pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#39,854
“impassable” frequency rank
#1,724
“impossible” frequency rank
41578
confusion score

Side-by-Side Comparison

Feature impassable impossible
Definition Incapable of being passed over, crossed, or negotiated. Not possible; not able to be done or happen.

Letter map: impassable vs impossible

Shared letters muted; letters that set impassable and impossible apart highlighted. Shared run: 8.

10 ch
impassable
10 ch
impossible

Pair insight - impassable / impossible

impassable and impossible are indexed as a confusable English pair. We have no recorded pronunciation or part of speech for both members, so the spelling overlap is what we can show you: they share most of their letters but differ in 2 positions. Our composite confusion score for this pair is 41578, derived from the frequency rank of both members and their visual similarity.

impassable is recorded at frequency rank #39,854, classified as anadj. impossible is at rank #1,724, tagged as anadj, pronounced /ɪmˈpɒs.ɪ.bəl/.

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 41578, this pair ranks #257,030 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of impassable vs impossible

Shared letters: beilmps. Private to "impassable": a. Private to "impossible": o.

"impassable" · 10 letters · shape VCCVCCVCCV  ·  "impossible" · 10 letters · shape VCCVCCVCCV

Known mistypes of this pair

  • impassableimapssable · immpassable · impasable · impasasble · impassabble · impassabel · impassablle · impassalbe
  • impossibleimmpossible · imopssible · imposible · imposisble · impossable · impossbile · impossibble · impossibel

Frequently Asked Questions

Is swapping "impassable" for "impossible" ever safe?
No. They share most of their letters but differ in 2 positions, but the dictionary glosses above give them different meanings, so swapping one for the other changes what the sentence says.
Frequency check: "impassable" vs "impossible" - which ranks higher?
"impossible" is the more common of the two: it sits at frequency rank #1,724 in our English list, against #39,854 for "impassable". 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 "impassable" and "impossible".

  • Full dictionary entry for "impassable" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "impossible" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #257,030 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "impassable" and "impossible" also get mixed up with nearby pairs, the highest-scored neighbour is "impossible vs impossibly". Nearby pair
  • Recorded mistypes exist for at least one side of this pair, useful when a spell-checker or OCR lands on the wrong form. See mistypes

Confusion rank #257,030 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