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gpt-oss-120b

OpenAI's larger open-weight reasoning model (117B total, 5.1B active parameters) under the Apache 2.0 license; fits on a single H100 GPU. Text input and output, 131,072-token context window.

Last verified Available 7 sources

Key specs

Provider
OpenAI
Family
gpt-oss
API identifier
gpt-oss-120b
Availability
Available
Release date
2025-08-05
License
Open source (Apache 2.0)
Context window
131,072 tokens
Max output
131,072 tokens
Knowledge cutoff
June 2024
API access
Unknown
Consumer app
Unknown

Capabilities

Inputs

  • Text input Yes
  • Image input No Model page marks image as not supported; text is the only modality
  • Audio input No Model page marks audio as not supported
  • Video input No Model page marks video as not supported
  • File input Unknown

Outputs

  • Text output Yes
  • Image output No Model page marks image as not supported; text is the only modality
  • Audio output No Model page marks audio as not supported

Features

  • Reasoning Native Configurable reasoning effort (low, medium, high) with full chain-of-thought access; no option to disable reasoning is documented
  • Tool calling Yes Function calling listed as a supported feature and Responses API tool; key features name native function calling, web browsing, Python code execution and structured outputs
  • Web search Yes Model page lists web_search among the tools supported with the Responses API (with function_calling, code_interpreter and mcp); key features also name native web browsing

"Unknown" means we have not verified this capability yet; it does not mean the model lacks it.

Pricing

No current prices listed.

Benchmarks

BenchmarkSettingScoreReported byMeasuredVerifiedSource
AutomationBench % tasks completed correctly, higher is better v1.0.6; high effort 0.15 % Third party — 2026-10-25 AutomationBench AI benchmark leaderboard (Zapier)
GDPval-AA v2.1 Elo, higher is better high effort 608 Elo Third party 2026-10-25 2026-10-25 GDPval-AA v2.1 Leaderboard (Artificial Analysis)
low effort 171 Elo Third party 2026-10-25 2026-10-25 GDPval-AA v2.1 Leaderboard (Artificial Analysis)
Humanity's Last Exam accuracy %, higher is better no tools; high effort 14.9 % Self-reported — 2026-10-25 gpt-oss-120b & gpt-oss-20b Model Card (OpenAI, arXiv 2508.10925)
no tools; low effort 5.2 % Self-reported — 2026-10-25 gpt-oss-120b & gpt-oss-20b Model Card (OpenAI, arXiv 2508.10925)
no tools; medium effort 8.6 % Self-reported — 2026-10-25 gpt-oss-120b & gpt-oss-20b Model Card (OpenAI, arXiv 2508.10925)
text-only subset; Scale Labs harness, o3-mini judge 15.48 % Third party — 2026-10-25 Humanity's Last Exam (Text Only) leaderboard (Scale Labs)
with tools; high effort 19 % Self-reported — 2026-10-25 gpt-oss-120b & gpt-oss-20b Model Card (OpenAI, arXiv 2508.10925)
with tools; low effort 9.1 % Self-reported — 2026-10-25 gpt-oss-120b & gpt-oss-20b Model Card (OpenAI, arXiv 2508.10925)
with tools; medium effort 11.3 % Self-reported — 2026-10-25 gpt-oss-120b & gpt-oss-20b Model Card (OpenAI, arXiv 2508.10925)
Text Arena Arena score, higher is better Overall, style control on 1,352 Third party 2026-10-23 2026-10-25 Text Arena leaderboard (Arena)
AutomationBench caveats:

Leaderboard versions (for example 1.0.5 and 1.0.6) are not comparable. Some results use fallback routing for refused steps: for "Claude Fable 5.1 (with Opus 5 Fallback)", Opus 5 handled 260 of 657 tasks. Artificial Analysis runs a separate leaderboard, AutomationBench-AA, which uses a guardrail-adjusted metric; its scores are not comparable with Zapier's. The partial_credit metric is for diagnostics only. The leaderboard shows no per-row evaluation dates.

GDPval-AA v2.1 caveats:

Elo is a relative rating: values change as models are added and the scale is re-anchored, so always store the date a rating was read. For example, Anthropic's launch page gives 1846 for Claude Opus 5.5, while the leaderboard on 2026-10-12 shows 1866 (Max, Default Fallback). Earlier versions (Google cites "GDPVal-AA v2") are not comparable. Judging is done by an LLM, not by human experts. Anthropic models are listed with "Default Fallback", meaning refused steps are routed to a fallback model. AA-Briefcase and GDP.pdf are separate evaluations.

Humanity's Last Exam caveats:

Results differ a lot by setting: with tools versus without tools (Anthropic reports 45.9% without tools and 57.4% with tools for Claude Haiku 5.5), and the full set versus the text-only subset. Providers use different judge models and harnesses (Scale uses o3-mini; Alibaba states GPT-4o). Derived sets such as HLE-Verified (a third-party revision with 1,811 scored items), HLE-Rolling and HLE-Diamond are different item sets and are not comparable. The questions are public, so contamination is possible, and community reviews have reported flawed items.

Text Arena caveats:

Scores measure voter preference, which can be influenced by answer style and length. The leaderboard offers a style-control adjustment, so record which view was used. Scores shift with every update, so a value is only meaningful together with its leaderboard date. Entries marked "Preliminary" or with few votes have wide confidence intervals. The same model can appear several times with different reasoning-effort suffixes (for example -high or -max). Category views (Coding, Math, Creative Writing and others) are different rankings from Overall.

One row per result, without rank numbers: each result was measured under its own setting (effort level, harness, tools, test version), as stated by the source, and scores compare only within the same setting. Self-reported results come from the provider and have not been reproduced independently.

Rankings

Derived from our published ranking snapshots; each ranking explains its criteria and weights.

Compare gpt-oss-120b

Guides

About gpt-oss-120b

gpt-oss-120b is the larger of OpenAI's two open-weight gpt-oss language models, with 117B total parameters and 5.1B active parameters, and fits on a single H100 GPU. It is released under the Apache 2.0 license with weights available on Hugging Face. It supports configurable reasoning effort (low, medium, high), full chain-of-thought access, function calling and structured outputs, and OpenAI describes it as fine-tunable.

Strengths and weaknesses

Strengths

  • Open weights under the Apache 2.0 license; can be self-hosted and fine-tuned
  • Configurable reasoning effort (low, medium, high) with full chain-of-thought access
  • Native function calling, web browsing, Python code execution and structured outputs
  • Runs on a single 80 GB GPU (H100)

Weaknesses

  • Text-only input and output (no image input)
  • 131,072-token context window and June 2024 knowledge cutoff, smaller and earlier than the GPT-6 models
  • No OpenAI API price is listed on the pricing page, and the model page shows rate limits of 0 for all API usage tiers

Sources

  1. gpt-oss-120b Model | OpenAI API
  2. Introducing gpt-oss | OpenAI
  3. gpt-oss-120b & gpt-oss-20b Model Card (OpenAI, arXiv 2508.10925)
  4. Humanity's Last Exam (Text Only) leaderboard (Scale Labs)
  5. GDPval-AA v2.1 Leaderboard (Artificial Analysis)
  6. AutomationBench AI benchmark leaderboard (Zapier)
  7. Text Arena leaderboard (Arena)

Last verified Page updated 2026-10-26