checkvscheckupWhich spelling fits?

Which to use

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

#487
“check” frequency rank
#33,563
“checkup” frequency rank
34050
confusion score

Side-by-Side Comparison

Feature check checkup
Definition An inspection or examination. A routine visit to the doctor, dentist, or the like.

Where the eye mixes check and checkup

Muted = shared; highlighted = the visual trap. They share 5 letters in sequence.

5 ch
check
7 ch
checkup

Why the eye confuses check with checkup

A purely visual mix-up. check (/t͡ʃɛk/) and checkup (/ˈt͡ʃɛkʌp/) 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 2 extra letter(s) - “check” sits inside “checkup”. Our composite confusion score for this pair is 34050, derived from the frequency rank of both members and their visual similarity.

check is recorded at frequency rank #487, classified as anoun, pronounced /t͡ʃɛk/. checkup is at rank #33,563, tagged as anoun, pronounced /ˈt͡ʃɛkʌp/.

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 34050, this pair ranks #324,091 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of check vs checkup

Shared letters: cehk. Private to "check": -. Private to "checkup": pu.

"check" · 5 letters · shape CCVCC  ·  "checkup" · 7 letters · shape CCVCCVC

Known mistypes of this pair

  • checkccheck · cehck · chcek · checck · checkk · chekc · chheck · hceck
  • checkupccheckup · cehckup · chcekup · checckup · checkkup · checkpu · checkupp · checukp

Frequently Asked Questions

Is swapping "check" for "checkup" ever safe?
No. They are said differently (/t͡ʃɛk/ versus /ˈt͡ʃɛkʌp/) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.
Which is more common, "check" or "checkup"?
"check" is the more common of the two: it sits at frequency rank #487 in our English list, against #33,563 for "checkup". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

Useful next steps

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

  • Full dictionary entry for "check" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "checkup" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #324,091 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "check" and "checkup" also get mixed up with nearby pairs, the highest-scored neighbour is "checker vs checkup". 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 #324,091 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