AufbauvsAusbauTell them apart

Which to use

“Aufbau” and “Ausbau” are a confusable German pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#2,189
“Aufbau” frequency rank
#3,170
“Ausbau” frequency rank
5359
confusion score

Side-by-Side Comparison

Feature Aufbau Ausbau
Definition der Vorgang des Aufbauens eines Gebäudes, eines Systems oder einer sonstwie gearteten Struktur planmäßige Vergrößerung, Erweiterung von etwas Bestehendem

Where the eye mixes Aufbau and Ausbau

Muted = shared; highlighted = the visual trap. They share 5 letters in sequence. Aufbau and Ausbau follow the identical consonant-vowel pattern (VVCCVV). Same shape at a glance is often the real trap, independent of shared letters.

6 ch
Aufbau
6 ch
Ausbau

Why the eye confuses Aufbau with Ausbau

A purely visual mix-up. Aufbau ([ˈaʊ̯fˌbaʊ̯]) and Ausbau ([ˈaʊ̯sˌbaʊ̯]) are said differently, so reading them aloud is the quickest way to catch the wrong one. On the page they stay close: they differ by a single letter - f in “Aufbau” becomes s in “Ausbau”. Our composite confusion score for this pair is 5359, derived from the frequency rank of both members and their visual similarity.

Aufbau is recorded at frequency rank #2,189, classified as anoun, pronounced [ˈaʊ̯fˌbaʊ̯]. Ausbau is at rank #3,170, tagged as anoun, pronounced [ˈaʊ̯sˌbaʊ̯].

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 5359, this pair ranks #1,995,005 of 2,006,359 scored German confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of Aufbau vs Ausbau

Shared letters: abu. Private to "Aufbau": f. Private to "Ausbau": s.

"Aufbau" · 6 letters · shape VVCCVV  ·  "Ausbau" · 6 letters · shape VVCCVV

Known mistypes of this pair

  • Aufbau ← afubau · aubfau · aufabu · aufbbau · aufbua · auffbau · uafbau
  • Ausbau ← asubau · aubsau · ausabu · ausbbau · ausbua · aussbau · uasbau

Frequently Asked Questions

Is swapping "Aufbau" for "Ausbau" ever safe?
No. They are said differently ([ˈaʊ̯fˌbaʊ̯] versus [ˈaʊ̯sˌbaʊ̯]) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.
Frequency check: "Aufbau" vs "Ausbau" - which ranks higher?
"Aufbau" is the more common of the two: it sits at frequency rank #2,189 in our German list, against #3,170 for "Ausbau". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Useful next steps

Visual near-miss handled. Browse the word pages or a neighbour when the next look-alike shows up.

  • Full dictionary entry for "Aufbau" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "Ausbau" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #1,995,005 of 2,006,359 scored German confusable pairs in this corpus vintage. Corpus statistics
  • "Aufbau" and "Ausbau" also get mixed up with nearby pairs, the highest-scored neighbour is "Ausbau vs ausgab". 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 #1,995,005 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