GPT OSS 20B vs Gemini 2.5 Flash Preview (thinking)

Compare GPT OSS 20B by OpenAI against Gemini 2.5 Flash Preview (thinking) by Google AI, in 6 community votes, gpt oss 20b and gemini 2.5 flash preview (thinking) are closely matched, context windows of 131K vs 1.0M, tested across 20 shared challenges. Updated February 2026.

In 6 community votes, GPT OSS 20B and Gemini 2.5 Flash Preview (thinking) are closely matched. GPT OSS 20B and Gemini 2.5 Flash Preview (thinking) perform similarly across challenge categories. Based on blind community voting from the RIVAL open dataset of 6+ human preference judgments for this pair.

Web Design: GPT OSS 20B and Gemini 2.5 Flash Preview (thinking) are tied
Image Generation: GPT OSS 20B and Gemini 2.5 Flash Preview (thinking) are tied
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