prior vs prob, What's the Difference?

Which to use

“prior” is an adjective and “prob” is a noun - they look or sound alike but fill different roles in a sentence.

#1,493
“prior” frequency rank: #17,003
“prob” frequency rank: 18496
confusion score

Side-by-Side Comparison

Feature	prior	prob
Definition	Coming before in order or time; earlier, former, previous.	Clipping of problem.

Letter map: prior vs prob

Shared letters muted; letters that set prior and prob apart highlighted. Shared run: 3.

5 ch

prior

4 ch

prob

Grammar separator: prior vs prob

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: prior is anadjective and probanoun. On the page they differ by 1 letter(s) in length. Our composite confusion score for this pair is 18496, derived from the frequency rank of both members and their visual similarity.

prior is recorded at frequency rank #1,493, classified as anadj, pronounced /ˈpɹaɪ.ə/. prob is at rank #17,003, tagged as anoun.

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 18496, this pair ranks #444,507 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of prior vs prob

Shared letters: opr. Private to "prior": i. Private to "prob": b.

"prior" · 5 letters · shape CCVVC · "prob" · 4 letters · shape CCVC

Known mistypes of this pair

prior ← piror · pprior · priorr · priro · proir · prrior · rpior
prob ← porb · pprob · prbo · probb · prrob · rpob

Frequently Asked Questions

Can "prior" and "prob" be used interchangeably?

No - they are not even the same part of speech. "prior" is an adjective and "prob" a noun, so a sentence built for one is usually ungrammatical with the other.

In ordinary English text, does "prior" or "prob" show up more?

"prior" is the more common of the two: it sits at frequency rank #1,493 in our English list, against #17,003 for "prob". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

After this comparison

You've compared "prior" and "prob". Here's where to go from here.

Full dictionary entry for "prior" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "prob" - compare definitions side by side with the headword page. Word entry
This pair ranks #444,507 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
"prior" and "prob" also get mixed up with nearby pairs, the highest-scored neighbour is "poon vs prob". 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 #444,507 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.