Model profile / OpenAI

GPT-OSS 20B

GPT-OSS 20B is a open weight model variant recorded in the BenchLM public dataset.

5 Aug 2025Open weightsProvider

Sources & details

Four areas of evidence

The capabilities behind the model.

How the indices work

Reasoning

No current rating

Mathematical and scientific problem solving.

Awaiting a qualified category score

Coding

No current rating

Software engineering and programming.

Awaiting a qualified category score

General

No current rating

Factual reliability and instruction following.

Awaiting a qualified category score

Agentic

No current rating

Tool use, workflows and professional tasks.

Awaiting a qualified category score

8retained native records

7evidence families

Capabilities estimateQualified original evidence across four areas.

Current index snapshot · 2026-09-16. Each category uses its own scale; scores across categories are not directly comparable. Evidence counts describe the retained Capabilities inputs; a family can contain several tasks or configurations. A point lead does not establish superiority.

Performance in context

Capabilities, price & speed.

Explore every model

GPT-OSS 20B is highlighted wherever a compatible measurement is available.

GPT-OSS 20B: OpenAI open weights; no first-party hosted API token price

Lumina Capabilities Index

Capabilities versus API price

The current Capabilities cohort, with this model highlighted.

Lumina

2025+ · 62 models · 1 highlighted

Chart loads as you explore

Lumina Capabilities Index

Capabilities versus output speed

The current Capabilities cohort, with this model highlighted.

Lumina

2025+ · 72 models · Developer API · 10K · 1 highlighted

Chart loads as you explore

Explore the detail

Sources & model details.

Original evidence, with its context.

Current index evidence 1Scores, research ranges and the sources behind each category.

Capabilities

Score uses the admitted direct native evidence under the selected method.

Exact checkpoint: gpt-oss-20b
Method: methods-a4471cee84fd478d2ed3
Range interpretation: C1 native factor under conditional crossed source/family reweighting of admitted fixed-corpus reference and own portfolio
Sources: Artificial Analysis:Artificial Analysis · Epoch AI:Epoch AI
Source cutoff: {"asOfMeaning":"Selected local candidate: retained historical measurements plus reviewed additions; execution dates remain source-native.","newIdentityRecovery":"2026-09-13T08:41:08.804270+00:00","publicProjectionDate":"2026-09-16T06:02:45.491398+00:00","scoring":"Inherited pinned baseline source vintages plus retained4A/4A.1 originals and SWE owner correction; heterogeneous execution dates, often unknown. Not a claim of simultaneous2026-09-13 execution."}

Explore this index

Benchmark measurements 52Published values in each benchmark’s own units.

52 measurements

GPT-OSS 20B published benchmark measurements
Benchmark	Result	Published configuration	Source
Artificial Analysis Agentic Index2026	3.1 index	Exact BenchLM registry variant GPT-OSS 20B; bulk export does not retain a complete upstream harness configuration.Source-native system	BenchLM public datasets — 21 July 2026 ↗Observed 2026-07-21 · checked 2026-07-21source-checked · reference-only
Artificial Analysis Agentic Index2026	3.1 index	Exact BenchLM registry variant GPT-OSS 20B; bulk export does not retain a complete upstream harness configuration.Source-native system	BenchLM public datasets — 2026-07-27 ↗Observed 2026-07-27 · checked 2026-07-27source-checked · reference-only
Artificial Analysis Agentic Index2026	3.1 index	Exact BenchLM registry variant GPT-OSS 20B; bulk export does not retain a complete upstream harness configuration.Source-native system	BenchLM public datasets — 2026-08-01 ↗Observed 2026-08-01 · checked 2026-08-01source-checked · reference-only
Artificial Analysis Coding Index2026	20.7 index	Exact BenchLM registry variant GPT-OSS 20B; bulk export does not retain a complete upstream harness configuration.Source-native system	BenchLM public datasets — 21 July 2026 ↗Observed 2026-07-21 · checked 2026-07-21source-checked · reference-only
Artificial Analysis Coding Index2026	20.7 index	Exact BenchLM registry variant GPT-OSS 20B; bulk export does not retain a complete upstream harness configuration.Source-native system	BenchLM public datasets — 2026-07-27 ↗Observed 2026-07-27 · checked 2026-07-27source-checked · reference-only
Artificial Analysis Coding Index2026	20.7 index	Exact BenchLM registry variant GPT-OSS 20B; bulk export does not retain a complete upstream harness configuration.Source-native system	BenchLM public datasets — 2026-08-01 ↗Observed 2026-08-01 · checked 2026-08-01source-checked · reference-only
GPQA Diamond2026	68.8%	Exact BenchLM registry variant GPT-OSS 20B; bulk export does not retain a complete upstream harness configuration.Source-native system	BenchLM public datasets — 21 July 2026 ↗Observed 2026-07-21 · checked 2026-07-21source-checked · reference-only
GPQA Diamond2026	68.8%	Exact BenchLM registry variant GPT-OSS 20B; bulk export does not retain a complete upstream harness configuration.Source-native system	BenchLM public datasets — 2026-07-27 ↗Observed 2026-07-27 · checked 2026-07-27source-checked · reference-only
GPQA Diamond2026	68.8%	Exact BenchLM registry variant GPT-OSS 20B; bulk export does not retain a complete upstream harness configuration.Source-native system	BenchLM public datasets — 2026-08-01 ↗Observed 2026-08-01 · checked 2026-08-01source-checked · reference-only
Humanity's Last Exam2026	9.8%	Exact BenchLM registry variant GPT-OSS 20B; bulk export does not retain a complete upstream harness configuration.Source-native system	BenchLM public datasets — 21 July 2026 ↗Observed 2026-07-21 · checked 2026-07-21source-checked · reference-only

Showing 10 of 52 measurements

Specifications & source recordsDocumented model details and original references.

Model ID / checkpoint: gpt-oss-20b
Weight access: Open weights
Context window: 128,000
Maximum output: Not documented
Modalities: text
Details checked: 1 Aug 2026

Artificial Analysis LLM data API — 2026-07-27Artificial Analysis · Published 27 Jul 2026 · checked 27 Jul 2026 · source-checked Artificial Analysis LLM data API — 2026-08-01Artificial Analysis · Published 1 Aug 2026 · checked 1 Aug 2026 · source-checked Artificial Analysis Free API — 21 July 2026Artificial Analysis · Published 21 Jul 2026 · checked 21 Jul 2026 · source-checked BenchLM public datasets — 21 July 2026BenchLM · Published 21 Jul 2026 · checked 21 Jul 2026 · source-checked BenchLM public datasets — 2026-07-27BenchLM · Published 27 Jul 2026 · checked 27 Jul 2026 · source-checked BenchLM public datasets — 2026-08-01BenchLM · Published 1 Aug 2026 · checked 1 Aug 2026 · source-checked Epoch AI permanent refresh sourceEpoch AI · checked 1 Sept 2026 · source-checked

Specialist task evidenceSeparate agent runs and execution conditions.

All models

Model profile / OpenAI

GPT-OSS 20B

GPT-OSS 20B is a open weight model variant recorded in the BenchLM public dataset.

5 Aug 2025Open weightsProvider

Sources & details

Four areas of evidence

The capabilities behind the model.

How the indices work

Reasoning

No current rating

Mathematical and scientific problem solving.

Awaiting a qualified category score

Coding

No current rating

Software engineering and programming.

Awaiting a qualified category score

General

No current rating

Factual reliability and instruction following.

Awaiting a qualified category score

Agentic

No current rating

Tool use, workflows and professional tasks.

Awaiting a qualified category score

8retained native records

7evidence families

Capabilities estimateQualified original evidence across four areas.

Performance in context

Capabilities, price & speed.

Explore every model

GPT-OSS 20B is highlighted wherever a compatible measurement is available.

GPT-OSS 20B: OpenAI open weights; no first-party hosted API token price

Lumina Capabilities Index

Capabilities versus API price

The current Capabilities cohort, with this model highlighted.

Lumina

2025+ · 62 models · 1 highlighted

Chart loads as you explore

Lumina Capabilities Index

Capabilities versus output speed

The current Capabilities cohort, with this model highlighted.

Lumina

2025+ · 72 models · Developer API · 10K · 1 highlighted

Chart loads as you explore

Explore the detail

Sources & model details.

Original evidence, with its context.

Current index evidence 1Scores, research ranges and the sources behind each category.

Capabilities

Score uses the admitted direct native evidence under the selected method.

Exact checkpoint: gpt-oss-20b
Method: methods-a4471cee84fd478d2ed3
Range interpretation: C1 native factor under conditional crossed source/family reweighting of admitted fixed-corpus reference and own portfolio
Sources: Artificial Analysis:Artificial Analysis · Epoch AI:Epoch AI
Source cutoff: {"asOfMeaning":"Selected local candidate: retained historical measurements plus reviewed additions; execution dates remain source-native.","newIdentityRecovery":"2026-09-13T08:41:08.804270+00:00","publicProjectionDate":"2026-09-16T06:02:45.491398+00:00","scoring":"Inherited pinned baseline source vintages plus retained4A/4A.1 originals and SWE owner correction; heterogeneous execution dates, often unknown. Not a claim of simultaneous2026-09-13 execution."}

Explore this index

Benchmark measurements 52Published values in each benchmark’s own units.

52 measurements

GPT-OSS 20B published benchmark measurements
Benchmark	Result	Published configuration	Source
Artificial Analysis Agentic Index2026	3.1 index	Exact BenchLM registry variant GPT-OSS 20B; bulk export does not retain a complete upstream harness configuration.Source-native system	BenchLM public datasets — 21 July 2026 ↗Observed 2026-07-21 · checked 2026-07-21source-checked · reference-only
Artificial Analysis Agentic Index2026	3.1 index	Exact BenchLM registry variant GPT-OSS 20B; bulk export does not retain a complete upstream harness configuration.Source-native system	BenchLM public datasets — 2026-07-27 ↗Observed 2026-07-27 · checked 2026-07-27source-checked · reference-only
Artificial Analysis Agentic Index2026	3.1 index	Exact BenchLM registry variant GPT-OSS 20B; bulk export does not retain a complete upstream harness configuration.Source-native system	BenchLM public datasets — 2026-08-01 ↗Observed 2026-08-01 · checked 2026-08-01source-checked · reference-only
Artificial Analysis Coding Index2026	20.7 index	Exact BenchLM registry variant GPT-OSS 20B; bulk export does not retain a complete upstream harness configuration.Source-native system	BenchLM public datasets — 21 July 2026 ↗Observed 2026-07-21 · checked 2026-07-21source-checked · reference-only
Artificial Analysis Coding Index2026	20.7 index	Exact BenchLM registry variant GPT-OSS 20B; bulk export does not retain a complete upstream harness configuration.Source-native system	BenchLM public datasets — 2026-07-27 ↗Observed 2026-07-27 · checked 2026-07-27source-checked · reference-only
Artificial Analysis Coding Index2026	20.7 index	Exact BenchLM registry variant GPT-OSS 20B; bulk export does not retain a complete upstream harness configuration.Source-native system	BenchLM public datasets — 2026-08-01 ↗Observed 2026-08-01 · checked 2026-08-01source-checked · reference-only
GPQA Diamond2026	68.8%	Exact BenchLM registry variant GPT-OSS 20B; bulk export does not retain a complete upstream harness configuration.Source-native system	BenchLM public datasets — 21 July 2026 ↗Observed 2026-07-21 · checked 2026-07-21source-checked · reference-only
GPQA Diamond2026	68.8%	Exact BenchLM registry variant GPT-OSS 20B; bulk export does not retain a complete upstream harness configuration.Source-native system	BenchLM public datasets — 2026-07-27 ↗Observed 2026-07-27 · checked 2026-07-27source-checked · reference-only
GPQA Diamond2026	68.8%	Exact BenchLM registry variant GPT-OSS 20B; bulk export does not retain a complete upstream harness configuration.Source-native system	BenchLM public datasets — 2026-08-01 ↗Observed 2026-08-01 · checked 2026-08-01source-checked · reference-only
Humanity's Last Exam2026	9.8%	Exact BenchLM registry variant GPT-OSS 20B; bulk export does not retain a complete upstream harness configuration.Source-native system	BenchLM public datasets — 21 July 2026 ↗Observed 2026-07-21 · checked 2026-07-21source-checked · reference-only

Showing 10 of 52 measurements

Specifications & source recordsDocumented model details and original references.

Model ID / checkpoint: gpt-oss-20b
Weight access: Open weights
Context window: 128,000
Maximum output: Not documented
Modalities: text
Details checked: 1 Aug 2026

Specialist task evidenceSeparate agent runs and execution conditions.

The capabilities behind the model.

Capabilities, price & speed.

Capabilities versus API price

Capabilities versus output speed

Sources & model details.

Capabilities

More from OpenAI.

GPT-6 Astra

GPT-5.6 Sol

GPT-5.6 Terra

The capabilities behind the model.

Capabilities, price & speed.

Capabilities versus API price

Capabilities versus output speed

Sources & model details.

Capabilities

More from OpenAI.

GPT-6 Astra

GPT-5.6 Sol

GPT-5.6 Terra