radioaktivevsradioaktiverWhich spelling fits?

Which to use

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

#28,341
“radioaktive” frequency rank
#42,748
“radioaktiver” frequency rank
71089
confusion score

Side-by-Side Comparison

Feature radioaktive radioaktiver
Definition Nominativ Singular Femininum der starken Deklination des Positivs des Adjektivs radioaktiv Nominativ Singular Maskulinum der starken Deklination des Positivs des Adjektivs radioaktiv

Where the eye mixes radioaktive and radioaktiver

Muted = shared; highlighted = the visual trap. They share 11 letters in sequence. radioaktive runs 11 letters (CVCVVVCCVCV) against radioaktiver's 12 (CVCVVVCCVCVC) - the length gap alone is often enough to separate them once you know to check it.

11 ch
radioaktive
12 ch
radioaktiver

Why the eye confuses radioaktive with radioaktiver

A purely visual mix-up. radioaktive ([ˌʁadi̯oʔakˈtiːvə]) and radioaktiver ([ˌʁadi̯oʔakˈtiːvɐ]) 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 1 extra letter(s) - “radioaktive” sits inside “radioaktiver”. Our composite confusion score for this pair is 71089, derived from the frequency rank of both members and their visual similarity.

radioaktive is recorded at frequency rank #28,341, classified as anadj, pronounced [ˌʁadi̯oʔakˈtiːvə]. radioaktiver is at rank #42,748, tagged as anadj, pronounced [ˌʁadi̯oʔakˈtiːvɐ].

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 71089, this pair ranks #427,100 of 2,006,359 scored German confusable pairs - among the most confusable pairs.

Orthographic DNA of radioaktive vs radioaktiver

Shared letters: adeikortv. Private to "radioaktive": -. Private to "radioaktiver": -.

"radioaktive" · 11 letters · shape CVCVVVCCVCV  ·  "radioaktiver" · 12 letters · shape CVCVVVCCVCVC

Known mistypes of this pair

  • radioaktive ← ardioaktive · raddioaktive · radiaoktive · radioakitve · radioakktive · radioaktiev · radioaktivve · radioakttive
  • radioaktiver ← ardioaktiver · raddioaktiver · radiaoktiver · radioakitver · radioakktiver · radioaktievr · radioaktiverr · radioaktivre

Frequently Asked Questions

Can "radioaktive" and "radioaktiver" be used interchangeably?
No. They are said differently ([ˌʁadi̯oʔakˈtiːvə] versus [ˌʁadi̯oʔakˈtiːvɐ]) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.
In ordinary German text, does "radioaktive" or "radioaktiver" show up more?
"radioaktive" is the more common of the two: it sits at frequency rank #28,341 in our German list, against #42,748 for "radioaktiver". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

Eye-level mix-up between "radioaktive" and "radioaktiver" is sorted above. Next: full entries or other pairs that share a letter shape.

  • Full dictionary entry for "radioaktive" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "radioaktiver" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #427,100 of 2,006,359 scored German confusable pairs in this corpus vintage. Corpus statistics
  • "radioaktive" and "radioaktiver" also get mixed up with nearby pairs, the highest-scored neighbour is "radioaktiv vs radioaktiver". 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 #427,100 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