filvsflyTell them apart

Which to use

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

#19,085
“fil” frequency rank
#1,827
“fly” frequency rank
20912
confusion score

Side-by-Side Comparison

Feature fil fly
Definition A Nordic dairy product, similar to yogurt, but using different bacteria which give a different taste and texture. Any insect of the order Diptera; characterized by having two wings (except for some wingless species), also called true flies.

Where the eye mixes fil and fly

Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.

3 ch
fil
3 ch
fly

Why the eye confuses fil with fly

A purely visual mix-up. fil (/fiːl/) 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 share most of their letters but differ in 2 positions. Our composite confusion score for this pair is 20912, derived from the frequency rank of both members and their visual similarity.

fil is recorded at frequency rank #19,085, classified as anoun, pronounced /fiːl/. 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 20912, this pair ranks #427,765 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of fil vs fly

Shared letters: fl. Private to "fil": i. Private to "fly": y.

"fil" · 3 letters · shape CVC  ·  "fly" · 3 letters · shape CCV

Frequently Asked Questions

Is swapping "fil" for "fly" ever safe?
No. They are said differently (/fiːl/ versus /flaɪ/) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.
In ordinary English text, does "fil" or "fly" show up more?
"fly" is the more common of the two: it sits at frequency rank #1,827 in our English list, against #19,085 for "fil". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

After this comparison

Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.

  • Full dictionary entry for "fil" 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 #427,765 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "fil" and "fly" also get mixed up with nearby pairs, the highest-scored neighbour is "fil vs foh". Nearby pair

Confusion rank #427,765 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