Which to use
“FBI” and “FSB” are a confusable French pair: similar on the page, but distinct in meaning, check the gloss before you choose.
- #9,163
- “FBI” frequency rank
- #45,626
- “FSB” frequency rank
- 54789
- confusion score
Side-by-Side Comparison
| Feature | FBI | FSB |
|---|---|---|
| Definition | Principal service fédéral de police judiciaire des États-Unis. | Service de renseignement de la Russie chargé des affaires de sécurité intérieure, successeur du service de la sécurité intérieure du KGB. |
Where the eye mixes FBI and FSB
Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.
Look-alike desk: FBI vs FSB
A purely visual mix-up. FBI (\ɛf.bi.aj\) and FSB (\ɛf.ɛs.be\) 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 54789, derived from the frequency rank of both members and their visual similarity.
FBI is recorded at frequency rank #9,163, classified as aname, pronounced \ɛf.bi.aj\. FSB is at rank #45,626, tagged as aname, pronounced \ɛf.ɛs.be\.
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 54789, this pair ranks #131,652 of 440,172 scored French confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of FBI vs FSB
Shared letters: bf. Private to "FBI": i. Private to "FSB": s.
"FBI" · 3 letters · shape CCV · "FSB" · 3 letters · shape CCC
Frequently Asked Questions
Is swapping "FBI" for "FSB" ever safe?
Frequency check: "FBI" vs "FSB" - which ranks higher?
Useful next steps
Eye-level mix-up between "FBI" and "FSB" is sorted above. Next: full entries or other pairs that share a letter shape.
- Full dictionary entry for "FBI" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "FSB" - compare definitions side by side with the headword page. Word entry
- This pair ranks #131,652 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
- "FBI" and "FSB" also get mixed up with nearby pairs, the highest-scored neighbour is "Fee vs FSB". Nearby pair
Confusion rank #131,652 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.