Detect AI in German text.

• 1Compound noun construction patterns differ from natural German use
• 2Verb-final clause structures sometimes incorrectly parsed
• 3Sie/du formality boundaries inconsistent in AI German
• 4Loanword integration follows English patterns, not German

German AI detection, in detail.

German AI detection has unique signals because the language's compound noun construction and verb-final clause structure stress-test LLMs differently than English does. AI-generated German often produces compound nouns that are technically valid but stylistically unusual ("Inhaltserstellungsverfahren" when a native speaker would say "Verfahren zur Inhaltserstellung"), and the verb-final clause patterns sometimes show up at incorrect positions for the register. AI Checker is calibrated for standard High German (de-DE) and Austrian German (de-AT), with detection accuracy around 95% on unedited output. The Sie/du formality distinction is a particular tell: AI German often defaults to overly formal Sie even when the prompt suggests casual du, a pattern human writers usually avoid. For technical and legal German contexts, we maintain higher-accuracy specialized models in the enterprise tier.

German detection in depth.

German is a stress test for LLMs because the language's structural features — compound noun construction, verb-final clauses in subordinate sentences, Sie/du formality distinction, four grammatical cases — all create opportunities for AI models to produce text that's grammatically correct but stylistically off. AI Checker's German detection head exploits all of these. The compound noun signal is particularly diagnostic. AI German often coins compound nouns that are grammatically valid but stylistically unusual — "Inhaltserstellungsverfahren" is technically correct but a native writer would prefer "Verfahren zur Inhaltserstellung" for readability. AI models default to compounds because they're treated as single tokens during training, but native German writers balance compound and analytic constructions for readability. Verb-final clause structures are another signal: AI German sometimes places the verb at the end of clauses where the register would call for analytic structure, and other times misses verb-final placement where it's required. The Sie/du formality distinction is a high-leverage marker: AI German over-defaults to formal Sie even when the prompt explicitly requests casual du, a pattern native writers naturally avoid because over-formality reads as cold. AI Checker reaches 94-96% accuracy on unedited German across GPT-4, Claude, and Gemini output. Calibration covers standard High German (de-DE) and Austrian German (de-AT) separately; Swiss German written communication uses the de-DE calibration with slight accuracy degradation. For technical, legal, and academic German contexts where formal register is correct, AI Checker's enterprise tier provides specialized calibration that doesn't false-positive on legitimately formal native writing — important for users in EU institutional, financial services, and pharmaceutical regulatory contexts.

Detection by model, audience, and comparison.