Claude recommends different brands by language, study finds
Search Engine Journal contributor Reza Moaiandin tested Claude Sonnet 5 on six shopping and travel scenarios across five languages — English, Arabic, Russian, Chinese and Persian — collecting 1,650 responses via DataForSEO’s LLM Responses API on September 7, 2026. For some categories the top brand swung sharply by language alone: asked about a London-to-Tenerife flight, Claude picked British Airways 52.5% of the time in Persian and not once in Russian, where it favored easyJet 72.5% of the time instead, while categories with fewer dominant global brands, like robot vacuums, stayed consistent across all five languages. A smaller comparison test found Gemini’s top pick matched Claude’s in five of ten language-category combinations and ChatGPT matched it in just one; the author cautions the dataset is small enough that some results may sit within the margin of error.
Why it matters: It's a concrete illustration that AI-visibility testing done only in English can miss how a brand is actually represented to non-English speakers, a gap the AEO practice has flagged but rarely measured directly.
The record: AnthropicChatGPTGemini
Posted to the wire October 13, 2026. Edited by Joe Balewski.