#51 gpt-oss-20b
Released: · SourceText; Coding; Reasoning; Agentic actions
- Use cases
- Agentic actions, Coding, Reasoning, Text
- Accepts
- Text & code
- Produces
- Text & code
- License
- Apache-2.0
Access
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