gpt-oss-20b

Name: gpt-oss-20b
Price: 20 USD
Availability: InStock
Author: OpenAI

Large Language ModelsOpen Weights

OpenAI

gpt-oss-20b is an open-weight 21B parameter model released by OpenAI under the Apache 2.0 license. It uses a Mixture-of-Experts (MoE) architecture with 3.6B active parameters per forward pass, optimized for...

Running this yourself: likely needs a rented cloud gpu.

Model updates refreshed12h agoAug 18, 2026news + changelog

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Archived

This model is still tracked for research and discovery, but it is excluded from default public rankings until it returns to active status.

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Quality Score

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Arena ELO

20B

Parameters

131K

Context

Benchmarks and Competitive Signal

Structured

Use this section to answer one simple question first: how much outside evidence do we have that this model performs well? Structured benchmark scores appear first, then official provider evidence, then live arena signal.

This model has normalized benchmark rows, so scores here are directly comparable across benchmark sources.

TerminalBench 2.0code

3.4

SWE-Bench

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Official Benchmark Evidence

These are recent benchmark or leaderboard claims from official provider sources. They are useful for freshness and context, but they are not treated the same as normalized independent benchmark rows.

Introducing GPT-5.2

Benchmarksprovider-benchmarksAug 18, 2026

Introducing GPT-5.2 | OpenAI Skip to main content Research Products Business Developers Company Foundation (opens in a new window) Log in Try ChatGPT (opens in a new window) Research Products Business Developers Company Foundation (opens in a new window) Try ChatGPT (opens in a new window) Login OpenAI December 11, 2025 Product Release Introducing GPT‑5.2 The most advanced frontier model for professional work and long-running agents. Loading… Share Model performance Model per

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Models | OpenAI API

Benchmarksprovider-benchmarksMay 5, 2026

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