Which to use
“foo” is a noun and “fro” is an adverb - they look or sound alike but fill different roles in a sentence.
- #18,562
- “foo” frequency rank
- #19,093
- “fro” frequency rank
- 37655
- confusion score
Side-by-Side Comparison
| Feature | foo | fro |
|---|---|---|
| Definition | Alternative form of fu: an administrative subdivision of imperial China; the capital of such divisions. | From; away; back or backward. |
Where the spellings diverge
Shared letters are muted; the letters that actually set foo and fro apart are highlighted. They share 2 letters in sequence, which is exactly why the eye skips the difference.
Spelling & Dictionary Insight
foo and fro form a confusable pair in the English index, two distinct headwords that are easily confused because they look alike, sound alike, or both. They differ by a single letter - o in “foo” becomes r in “fro” - close enough that the eye skips over the difference, far enough that meaning fully diverges. Our composite confusion score for this pair is 37655, derived from the frequency rank of both members and their visual similarity.
foo is recorded at frequency rank #18,562, classified as anoun, pronounced /fuː/. fro is at rank #19,093, tagged as anadv, pronounced /fɹəʊ/.
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 37655, this pair ranks #292,709 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.
Frequency comparison
Frequently Asked Questions
Can "foo" and "fro" be used interchangeably?
Remembering foo vs fro
The fastest way to pick the right one every time.
- Check the role first: if you need a noun, it's “foo”; for an adverb, it's “fro”.
- See each word in full, definition, IPA, etymology and its other confusables. Full “foo” entry
- Browse more pairs most likely to be confused. Most confusable