OpenAI LLM Medium Open weights

gpt-oss-20b

464 days since OpenAI announced it · 5 Aug 2025

gpt-oss-20b is an open-weights LLM from OpenAI, announced 5 Aug 2025. Its context window is 128K tokens. It has 21B parameters.

Input: —; per 1M tokens
Cache write: —; per 1M tokens
Cache read: —; per 1M tokens
Output: —; per 1M tokens
Context window: 128K; tokens
Parameters: 21B; total

No price on the lab’s own pages.

Announcement: openai.com/blog/introducing-gpt-oss
Docs: developers.openai.com/api/docs/models/gpt-oss-20b

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OpenAI · Medium · 20b

open weights

gpt-oss-20b 5 Aug 2025

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