FISvsfizzTell them apart

Which to use

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

#40,245
“FIS” frequency rank
#29,656
“fizz” frequency rank
69901
confusion score

Side-by-Side Comparison

Feature FIS fizz
Definition Initialism of flight information service. An emission of a rapid stream of bubbles.

Letter map: FIS vs fizz

Shared letters muted; letters that set FIS and fizz apart highlighted. Shared run: 2. FIS runs 3 letters (CVC) against fizz's 4 (CVCC) - the length gap alone is often enough to separate them once you know to check it.

3 ch
FIS
4 ch
fizz

Spelling & dictionary notes on FIS vs fizz

FIS and fizz 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 differ by 1 letter(s) in length. Our composite confusion score for this pair is 69901, derived from the frequency rank of both members and their visual similarity.

FIS is recorded at frequency rank #40,245, classified as anoun. fizz is at rank #29,656, tagged as anoun, pronounced /fɪz/.

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 69901, this pair ranks #52,679 of 530,003 scored English confusable pairs - among the most confusable pairs.

Orthographic DNA of FIS vs fizz

Shared letters: fi. Private to "FIS": s. Private to "fizz": z.

"FIS" · 3 letters · shape CVC  ·  "fizz" · 4 letters · shape CVCC

Known mistypes of this pair

  • fizz ← ffizz · fiz · fziz · ifzz

Frequently Asked Questions

Is swapping "FIS" for "fizz" ever safe?
No. They differ by 1 letter(s) in length, but the dictionary glosses above give them different meanings, so swapping one for the other changes what the sentence says.
Frequency check: "FIS" vs "fizz" - which ranks higher?
"fizz" is the more common of the two: it sits at frequency rank #29,656 in our English list, against #40,245 for "FIS". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

What to do next

Done with this confusable. These links stay specific to "FIS" and "fizz".

  • Full dictionary entry for "FIS" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "fizz" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #52,679 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "FIS" and "fizz" also get mixed up with nearby pairs, the highest-scored neighbour is "FIS vs foh". 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 #52,679 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