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Claude Opus 4.1 vs gpt-oss-20b

2 vs 0 benchmarks won

Anthropic
Claude Opus 4.1
OpenAI
gpt-oss-20b
Overview
CompanyAnthropicOpenAI
Release dateAug 5 2025Aug 5 2025
Model type
Open sourceNoYes
Specifications
Parameters
Context window
Benchmarks
Science reasoning
GPQA Diamond
80.9%
Software engineering
SWE-Bench Verified
74.5%
Multimodal understanding
MMMU
Timeline
Release gapReleased on the same day

Which is better: Claude Opus 4.1 or gpt-oss-20b?

Claude Opus 4.1 leads gpt-oss-20b on 2 of the tracked benchmarks (GPQA Diamond, SWE-Bench Verified, MMMU). Both models were released on the same day — Aug 5 2025.

gpt-oss-20b is an open-source / open-weight model; Claude Opus 4.1 is proprietary.

Direct benchmark comparisons are unavailable — at least one of these models has not published scores on GPQA Diamond, SWE-Bench Verified, or MMMU.

Frequently asked questions

When was Claude Opus 4.1 released?
Claude Opus 4.1 was released by Anthropic on Aug 5 2025.
When was gpt-oss-20b released?
gpt-oss-20b was released by OpenAI on Aug 5 2025.
Is Claude Opus 4.1 or gpt-oss-20b open source?
gpt-oss-20b is an open-source / open-weight model released by OpenAI. Claude Opus 4.1 is a proprietary model released by Anthropic.

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