FSB vs FSK, What's the Difference?

Which to use

“FSB” is a noun and “FSK” is an abbrev - they look or sound alike but fill different roles in a sentence.

#41,175
“FSB” frequency rank: #26,415
“FSK” frequency rank: 67590
confusion score

Side-by-Side Comparison

Feature	FSB	FSK
Definition	russischer Inlandsgeheimdienst und Geheimpolizei	freiwillige Selbstkontrolle der Filmwirtschaft (Altersbegrenzung bei Filmen)

Letter map: FSB vs FSK

Shared letters muted; letters that set FSB and FSK apart highlighted. Shared run: 2.

3 ch

FSB

3 ch

FSK

Role in the sentence - FSB and FSK

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: FSB is anoun and FSKanabbrev. On the page they differ by a single letter - b in “FSB” becomes k in “FSK”. Our composite confusion score for this pair is 67590, derived from the frequency rank of both members and their visual similarity.

FSB is recorded at frequency rank #41,175, classified as anoun, pronounced [ɛfʔɛsˈbeː]. FSK is at rank #26,415, tagged as anabbrev, pronounced […].

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 67590, this pair ranks #535,193 of 2,006,359 scored German confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of FSB vs FSK

Shared letters: fs. Private to "FSB": b. Private to "FSK": k.

"FSB" · 3 letters · shape CCC · "FSK" · 3 letters · shape CCC

Frequently Asked Questions

Is swapping "FSB" for "FSK" ever safe?

No - they are not even the same part of speech. "FSB" is a noun and "FSK" an abbrev, so a sentence built for one is usually ungrammatical with the other.

In ordinary German text, does "FSB" or "FSK" show up more?

"FSK" is the more common of the two: it sits at frequency rank #26,415 in our German list, against #41,175 for "FSB". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

You've compared "FSB" and "FSK". Here's where to go from here.

Full dictionary entry for "FSB" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "FSK" - compare definitions side by side with the headword page. Word entry
This pair ranks #535,193 of 2,006,359 scored German confusable pairs in this corpus vintage. Corpus statistics
"FSB" and "FSK" also get mixed up with nearby pairs, the highest-scored neighbour is "fist vs FSB". Nearby pair

Confusion rank #535,193 of 2,006,359 scored German pairs, corpus vintage 2026-09-03, not spelling advice.