flvsflexWhat's the difference?

Quick tell: fl is a abbrev, flex is a verb, so they fill different roles in a sentence.

Which to use

“fl” is an abbrev and “flex” is a verb - they look or sound alike but fill different roles in a sentence.

#13,360
“fl” frequency rank
#19,574
“flex” frequency rank
32934
confusion score

Side-by-Side Comparison

Feature fl flex
Definition Femtoliter (= 10⁻¹⁵ l, ein billiardstel Liter) 2. Person Singular Imperativ Präsens Aktiv des Verbs flexen

Letter map: fl vs flex

Shared letters muted; letters that set fl and flex apart highlighted. Shared run: 2.

2 ch
fl
4 ch
flex

Role in the sentence - fl and flex

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: fl is anabbrev and flexaverb. On the page they differ by 2 extra letter(s) - “fl” sits inside “flex”. Our composite confusion score for this pair is 32934, derived from the frequency rank of both members and their visual similarity.

fl is recorded at frequency rank #13,360, classified as anabbrev. flex is at rank #19,574, tagged as averb, pronounced [flɛks].

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 32934, this pair ranks #1,696,942 of 2,006,359 scored German confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of fl vs flex

Shared letters: fl. Private to "fl": -. Private to "flex": ex.

"fl" · 2 letters · shape CC  ·  "flex" · 4 letters · shape CCVC

Known mistypes of this pair

  • flexfelx · fflex · flexx · fllex · flxe · lfex

Frequently Asked Questions

Is swapping "fl" for "flex" ever safe?
No - they are not even the same part of speech. "fl" is an abbrev and "flex" a verb, so a sentence built for one is usually ungrammatical with the other.
In ordinary German text, does "fl" or "flex" show up more?
"fl" is the more common of the two: it sits at frequency rank #13,360 in our German list, against #19,574 for "flex". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

Pair "fl" vs "flex" is on the table, pick a follow-up below.

  • Full dictionary entry for "fl" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "flex" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #1,696,942 of 2,006,359 scored German confusable pairs in this corpus vintage. Corpus statistics
  • "fl" and "flex" also get mixed up with nearby pairs, the highest-scored neighbour is "Filet vs flex". Nearby pair
  • Recorded mistypes exist for at least one side of this pair, useful when a spell-checker or OCR lands on the wrong form. See mistypes

Confusion rank #1,696,942 of 2,006,359 scored German pairs, corpus vintage 2026-09-03, not spelling advice.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list