What the evidence says
- Developer
- OpenAI
- Released
- August 5, 2025
- Domains
- Language
- Tasks
- Language modeling/generation · Question answering
- Access
- Open weights (unrestricted)
- Weights
- Open weights
Across the boards
Each row is one named authority's own current view. Nothing is combined.
- LMArena overall
- 1317.2 · rank #229 · 10,620 battles · published July 20, 2026 · board
- LMArena coding arena
- 1369.4 · rank #205 · board
- LMArena creative writing arena
- 1238.3 · rank #266 · board
- LMArena instruction following arena
- 1281.2 · rank #246 · board
- LMArena hard prompts arena
- 1322.8 · rank #229 · board
- LMArena multi-turn arena
- 1291.5 · rank #242 · board
- LMArena long queries arena
- 1300.7 · rank #244 · board
- LMArena math arena
- 1335.9 · rank #189 · board
- EQ-Bench 3
- 1111.5 · rank #60
Benchmark results
Epoch AI Benchmarking Hub scores for this reviewed identity. Rows with a scaffold are system results, not bare-model results. Fraction-unit scores shown as percentages.
- Terminal-Bench
- 3.4% · Mini-SWE-Agent
Platform facts
OpenRouter's platform listing, retrieved July 22, 2026. Routed platform prices, not first-party provider prices.
- Input price
- $0.030 per 1M tokens
- Output price
- $0.13 per 1M tokens
- Context length
- 131,072 tokens
- Listed on OpenRouter
- August 5, 2025
Common questions
What is gpt-oss-20b?
gpt-oss-20b is a OpenAI model released August 5, 2025, according to Epoch AI's reviewed catalog record. The record classifies it under language.
How does gpt-oss-20b rank on LMArena?
In the LMArena style-controlled text snapshot published July 20, 2026, gpt-oss-20b holds official rank 229 with a rating of 1317.2 across 10,620 battles.
What does gpt-oss-20b cost?
OpenRouter lists it at $0.030 per million input tokens and $0.13 per million output tokens, retrieved July 22, 2026. Those are the platform's routed prices, not first-party provider prices.