GPT OSS 20B vs ChatGPT-4o (March 2025)

Compare GPT OSS 20B and ChatGPT-4o (March 2025), both from OpenAI, in 3 community votes, gpt oss 20b wins 67% of head-to-head duels, context windows of 131K vs 128K, tested across 32 shared challenges. Updated February 2026.

In 3 community votes, GPT OSS 20B wins 67% of head-to-head duels. GPT OSS 20B leads in Reasoning. Based on blind community voting from the RIVAL open dataset of 3+ human preference judgments for this pair.