Which to use
“foo” is a noun and “fun” is an adjective - they look or sound alike but fill different roles in a sentence.
- #43,447
- “foo” frequency rank
- #5,870
- “fun” frequency rank
- 49317
- confusion score
Side-by-Side Comparison
| Feature | foo | fun |
|---|---|---|
| Definition | Variable métasyntaxique en programmation informatique. | Amusant. |
Where the eye mixes foo and fun
Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.
Visual trap between foo and fun
These two trip readers on the page rather than in the ear: foo is \fu\ while fun is \fœn\. Spoken aloud the problem disappears. In writing it persists, because they share most of their letters but differ in 2 positions, and the parts of speech differ too (noun vs adjective), which is usually the fastest check. Our composite confusion score for this pair is 49317, derived from the frequency rank of both members and their visual similarity.
foo is recorded at frequency rank #43,447, classified as anoun, pronounced \fu\. fun is at rank #5,870, tagged as anadj, pronounced \fœn\.
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 49317, this pair ranks #171,685 of 440,172 scored French confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of foo vs fun
Shared letters: f. Private to "foo": o. Private to "fun": nu.
"foo" · 3 letters · shape CVV · "fun" · 3 letters · shape CVC
Frequently Asked Questions
Do "foo" and "fun" mean the same thing in a sentence?
Which is more common, "foo" or "fun"?
What to do next
Visual near-miss handled. Browse the word pages or a neighbour when the next look-alike shows up.
- Full dictionary entry for "foo" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "fun" - compare definitions side by side with the headword page. Word entry
- This pair ranks #171,685 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
- "foo" and "fun" also get mixed up with nearby pairs, the highest-scored neighbour is "Fee vs foo". Nearby pair
Confusion rank #171,685 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.