Which to use
“flue” and “fly” are a confusable English pair: similar on the page, but distinct in meaning, check the gloss before you choose.
- #38,401
- “flue” frequency rank
- #1,827
- “fly” frequency rank
- 40228
- confusion score
Side-by-Side Comparison
| Feature | flue | fly |
|---|---|---|
| Definition | A pipe or duct that carries gaseous combustion products away from the point of combustion (such as a furnace). | Any insect of the order Diptera; characterized by having two wings (except for some wingless species), also called true flies. |
Where the eye mixes flue and fly
Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.
Look-alike desk: flue vs fly
A purely visual mix-up. flue (/fluː/) and fly (/flaɪ/) 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 1 letter(s) in length. Our composite confusion score for this pair is 40228, derived from the frequency rank of both members and their visual similarity.
flue is recorded at frequency rank #38,401, classified as anoun, pronounced /fluː/. fly is at rank #1,827, tagged as anoun, pronounced /flaɪ/.
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 40228, this pair ranks #269,468 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of flue vs fly
Shared letters: fl. Private to "flue": eu. Private to "fly": y.
"flue" · 4 letters · shape CCVV · "fly" · 3 letters · shape CCV
Known mistypes of this pair
- flue ← fflue · fleu · fllue · lfue
Frequently Asked Questions
Do "flue" and "fly" mean the same thing in a sentence?
In ordinary English text, does "flue" or "fly" show up more?
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 "flue" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "fly" - compare definitions side by side with the headword page. Word entry
- This pair ranks #269,468 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "flue" and "fly" also get mixed up with nearby pairs, the highest-scored neighbour is "flue vs fou". 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 #269,468 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.