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#51 gpt-oss-20b

OpenAI · gpt-oss-20b

Released: · Source

Text; Coding; Reasoning; Agentic actions

Use cases
Agentic actions, Coding, Reasoning, Text
Accepts
Text & code
Produces
Text & code
License
Apache-2.0

Access

OpenAI · CLI Computing: Local
OpenAI · Download Computing: Local

Price USD

No verified data · Local: hardware costs apply

Evaluator & score

Composite index · published model-group index · 20.09.2026 · Higher is better

Snapshot: 2026-09-20 · 90% CI [133.26, 139.73]

Official Epoch AI index; combines own, third-party and developer-reported results. It is not a safety audit or a media-generation score.

Conditions

Epoch Capabilities Index; official model-group estimates

Official ECI model scores, Epoch AI, CC BY 4.0. Composite of own, third-party and developer-reported results. 90% bootstrap interval. Not a per-effort score; export date is the model release date, not measurement date. Methodology: https://epoch.ai/eci#documentation

Independent run · high · 20.09.2026 · Higher is better

Snapshot: 2026-09-20

Conditions

Chess Puzzles; Epoch AI own run; best score across scorers

Epoch AI own run; Chess Puzzles; version: gpt-oss-20b_high; mode: high; source id: fjgo9DvKNgVAGtitPvgpY7; file: chess_puzzles.csv. CC BY 4.0, Epoch AI. Snapshot 2026-09-20. Source column Best score (across scorers), not AIpedia's selection of the best effort.

Measurement date: 27.08.2026

Independent run · low · 20.09.2026 · Higher is better

Snapshot: 2026-09-20

Conditions

Chess Puzzles; Epoch AI own run; best score across scorers

Epoch AI own run; Chess Puzzles; version: gpt-oss-20b_low; mode: low; source id: QX76VGMs6CYv9BGBKMCCNW; file: chess_puzzles.csv. CC BY 4.0, Epoch AI. Snapshot 2026-09-20. Source column Best score (across scorers), not AIpedia's selection of the best effort.

Measurement date: 27.08.2026

Independent run · medium · 20.09.2026 · Higher is better

Snapshot: 2026-09-20

Conditions

Chess Puzzles; Epoch AI own run; best score across scorers

Epoch AI own run; Chess Puzzles; version: gpt-oss-20b_medium; mode: medium; source id: 9F6GMXWPSzWo3evzcpAkTd; file: chess_puzzles.csv. CC BY 4.0, Epoch AI. Snapshot 2026-09-20. Source column Best score (across scorers), not AIpedia's selection of the best effort.

Measurement date: 27.08.2026

Independent run · high · 20.09.2026 · Higher is better

Snapshot: 2026-09-20

Conditions

GPQA Diamond; Epoch AI own run; best score across scorers

Epoch AI own run; GPQA diamond; version: gpt-oss-20b_high; mode: high; source id: hYATFPeUnMq7Std2nLUVAJ; file: gpqa_diamond.csv. CC BY 4.0, Epoch AI. Snapshot 2026-09-20. Source column Best score (across scorers), not AIpedia's selection of the best effort.

Measurement date: 06.08.2026

Independent run · low · 20.09.2026 · Higher is better

Snapshot: 2026-09-20

Conditions

GPQA Diamond; Epoch AI own run; best score across scorers

Epoch AI own run; GPQA diamond; version: gpt-oss-20b_low; mode: low; source id: DCJQMqipndGxwMXe8BDGeg; file: gpqa_diamond.csv. CC BY 4.0, Epoch AI. Snapshot 2026-09-20. Source column Best score (across scorers), not AIpedia's selection of the best effort.

Measurement date: 27.08.2026

Independent run · medium · 20.09.2026 · Higher is better

Snapshot: 2026-09-20

Conditions

GPQA Diamond; Epoch AI own run; best score across scorers

Epoch AI own run; GPQA diamond; version: gpt-oss-20b_medium; mode: medium; source id: GEwyLqZT93Hp55fdtHrJhm; file: gpqa_diamond.csv. CC BY 4.0, Epoch AI. Snapshot 2026-09-20. Source column Best score (across scorers), not AIpedia's selection of the best effort.

Measurement date: 27.08.2026

Independent run · high · 20.09.2026 · Higher is better

Snapshot: 2026-09-20

Conditions

Mock AIME 2024/2025; Epoch AI own run; best score across scorers

Epoch AI own run; OTIS Mock AIME 2024-2025; version: gpt-oss-20b_high; mode: high; source id: GMngscbSmqoPbGZWNv2Jvw; file: otis_mock_aime_2024_2025.csv. CC BY 4.0, Epoch AI. Snapshot 2026-09-20. Source column Best score (across scorers), not AIpedia's selection of the best effort.

Measurement date: 27.08.2026

Independent run · low · 20.09.2026 · Higher is better

Snapshot: 2026-09-20

Conditions

Mock AIME 2024/2025; Epoch AI own run; best score across scorers

Epoch AI own run; OTIS Mock AIME 2024-2025; version: gpt-oss-20b_low; mode: low; source id: cMwETYmC6b4yKupyJfEHv2; file: otis_mock_aime_2024_2025.csv. CC BY 4.0, Epoch AI. Snapshot 2026-09-20. Source column Best score (across scorers), not AIpedia's selection of the best effort.

Measurement date: 27.08.2026

Independent run · medium · 20.09.2026 · Higher is better

Snapshot: 2026-09-20

Conditions

Mock AIME 2024/2025; Epoch AI own run; best score across scorers

Epoch AI own run; OTIS Mock AIME 2024-2025; version: gpt-oss-20b_medium; mode: medium; source id: DB8ja6pEZWGocQbdciyisL; file: otis_mock_aime_2024_2025.csv. CC BY 4.0, Epoch AI. Snapshot 2026-09-20. Source column Best score (across scorers), not AIpedia's selection of the best effort.

Measurement date: 27.08.2026

SourceVerified 19.09.2026