seivsseizeWhat's the difference?

Quick tell: sei is a noun, seize is a verb, so they fill different roles in a sentence.

Which to use

“sei” is a noun and “seize” is a verb - they look or sound alike but fill different roles in a sentence.

#34,681
“sei” frequency rank
#9,669
“seize” frequency rank
44350
confusion score

Side-by-Side Comparison

Feature sei seize
Definition A sei whale. To deliberately take hold of; to grab or capture.

Where the eye mixes sei and seize

Muted = shared; highlighted = the visual trap. They share 3 letters in sequence.

3 ch
sei
5 ch
seize

Look-alike desk: sei vs seize

These two trip readers on the page rather than in the ear: sei is /seɪ/ while seize is /siːz/. Spoken aloud the problem disappears. In writing it persists, because they differ by 2 extra letter(s) - “sei” sits inside “seize”, and the parts of speech differ too (noun vs verb), which is usually the fastest check. Our composite confusion score for this pair is 44350, derived from the frequency rank of both members and their visual similarity.

sei is recorded at frequency rank #34,681, classified as anoun, pronounced /seɪ/. seize is at rank #9,669, tagged as averb, pronounced /siːz/.

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 44350, this pair ranks #231,451 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of sei vs seize

Shared letters: eis. Private to "sei": -. Private to "seize": z.

"sei" · 3 letters · shape CVV  ·  "seize" · 5 letters · shape CVVCV

Known mistypes of this pair

  • seizeesize · seiez · seizze · sezie · sieze · sseize

Frequently Asked Questions

Do "sei" and "seize" mean the same thing in a sentence?
No - they are not even the same part of speech. "sei" is a noun and "seize" a verb, so a sentence built for one is usually ungrammatical with the other.
In ordinary English text, does "sei" or "seize" show up more?
"seize" is the more common of the two: it sits at frequency rank #9,669 in our English list, against #34,681 for "sei". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

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 "sei" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "seize" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #231,451 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "sei" and "seize" also get mixed up with nearby pairs, the highest-scored neighbour is "sei vs Sif". 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 #231,451 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