OpenAI
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Listed August 2025
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Open Weights
gpt-oss-20b
Arena #265 • score 1317 ±6
Open Weights model from OpenAI, listed August 2025. Arena text score 1317 (#265 of 414 entries). $0.02 input / $0.09 output per 1M tokens. 128K tokens context.
Parameters
21B total, 3.6B active (MoE)
Context Window
128K tokens
Input / 1M tokens
$0.018
Output / 1M tokens
$0.09
Benchmark Results
- Arena Text Elo: 1317 (#265 of 414 on arena.ai · ±6 · 10,418 votes · variant: gpt-oss-20b)
- AA Intelligence Index: 10 (Artificial Analysis v4.3 · best setting: gpt-oss-20b (Low) · checked 2026-10-11)
- AA Coding Index: 20.7 (Artificial Analysis v4.3 · best setting: gpt-oss-20b (High) · checked 2026-10-11)
- AA Agentic Index: 1.2 (Artificial Analysis v4.3 · best setting: gpt-oss-20b (High) · checked 2026-10-11)