OpenAI

gpt-oss-20b

Tool callingStructured outputReasoning
gpt-oss-20b model card cover

Open GPT reasoning model for self-hosted agents and controllable deployments

Context
131K
Released
1y ago
Parameters
20B
Input / 1M tokens
$0.02
Output / 1M tokens
$0.09
Cached input / 1M tokens
$0.009

Sources:models.devOpenRouter

Benchmarks

DeepSWE is the primary coding benchmark where an exact model evaluation exists. Other sourced evaluations appear below; missing scores are not zero.

Not evaluated in DeepSWE 1.1 as of 2026-09-22. Results are only shown for exact model versions in the official dataset. Official leaderboard.

Other published benchmarks

EvaluationReported score and source
GPQA diamond
46.0%
Epoch AI · gpt-oss-20b_high
Reasoning effort: high
Epoch AI evaluation
GPQA diamond
53.2%
Epoch AI · gpt-oss-20b_low
Reasoning effort: low
Epoch AI evaluation
GPQA diamond
60.8%
Epoch AI · gpt-oss-20b_medium
Reasoning effort: medium
Epoch AI evaluation
OTIS Mock AIME 2024-2025
50.8%
Epoch AI · gpt-oss-20b_high
Reasoning effort: high
Epoch AI evaluation
OTIS Mock AIME 2024-2025
40.3%
Epoch AI · gpt-oss-20b_low
Reasoning effort: low
Epoch AI evaluation
OTIS Mock AIME 2024-2025
65.3%
Epoch AI · gpt-oss-20b_medium
Reasoning effort: medium
Epoch AI evaluation
Terminal Bench
3.4%
Terminal-Bench v2 Leaderboard · gpt-oss-20b
Agent: Mini-SWE-Agent
Terminal-Bench v2 Leaderboard
Original-source terms apply
Terminal Bench
3.1%
Terminal-Bench v2 Leaderboard · gpt-oss-20b
Agent: Terminus 2
Terminal-Bench v2 Leaderboard
Original-source terms apply
Terminal Bench
3.4%
https://www.tbench.ai/leaderboard/terminal-bench/2.0 · gpt-oss-20b_unknown
Agent: Mini-SWE-Agent · Reasoning effort: unknown
https://www.tbench.ai/leaderboard/terminal-bench/2.0
Original-source terms apply
Terminal Bench
3.1%
https://www.tbench.ai/leaderboard/terminal-bench/2.0 · gpt-oss-20b_unknown
Agent: Terminus 2 · Reasoning effort: unknown
https://www.tbench.ai/leaderboard/terminal-bench/2.0
Original-source terms apply

Benchmark compilation: Epoch AI, Capabilities & benchmarking (CC BY attribution). Scores are converted to percentages and model names matched to the Vertical Tabs catalog. Individual evaluations are credited to their original sources. External results may carry separate licences and evaluation configurations; do not interpret scores from different harnesses as directly comparable.

Specifications

Developer
OpenAI
Model family
GPT
Type
Language model
Predecessor
—
Successor
—
Released
August 5, 2025
Model ID
openai/gpt-oss-20b
Openness
Open weights
License
—
Parameters
20B
Input modalities
text
Output modalities
text
Modality
text->text
Native context
128K
Tokenizer
GPT
Max output tokens
33K
Knowledge cutoff
2024-06-30
Hugging Face
openai/gpt-oss-20b
Source freshness
Metadata synced Oct 8, 2026, 10:17 PM UTC

Open-weight builds

Ollama variants

Every published Ollama tag matched to this model, including parameter editions, instruction/base variants, and quantized builds.

4 builds
VariantParametersTypeQuantizationSizeContextInput
gpt-oss:20b-cloud20Bcloud——128Ktext
gpt-oss:latest20B——14 GB128Ktext
gpt-oss:120b-cloud120Bcloud——128Ktext
gpt-oss:120b120B——65 GB128Ktext
Additional source evidence
Source model
openai/gpt-oss-20b
Source family
gpt-oss
Last updated
2025-08-05
Model context
131K
Model output limit
33K
Open weights
Yes
File attachments
No
Reasoning
Yes
Tool calling
Yes
Structured output
Yes
Temperature control
Yes

Downloadable weights

Complete source record (JSON)
{
  "id": "openai/gpt-oss-20b",
  "name": "GPT OSS 20B",
  "description": "Open GPT reasoning model for self-hosted agents and controllable deployments",
  "family": "gpt-oss",
  "last_updated": "2025-08-05",
  "attachment": false,
  "reasoning": true,
  "tool_call": true,
  "structured_output": true,
  "temperature": true,
  "modalities": {
    "input": [
      "text"
    ],
    "output": [
      "text"
    ]
  },
  "limit": {
    "context": 131072,
    "output": 32768
  },
  "release_date": "2025-08-05",
  "open_weights": true,
  "weights": [
    {
      "label": "Hugging Face",
      "url": "https://huggingface.co/openai/gpt-oss-20b"
    }
  ]
}

Infrastructure

Provider availability

All providers
ProviderEndpointContextInput /M tokensOutput /M tokensCached input /M tokensCache write /M tokensUptime 1dData handling
Darkbloomdarkbloom/fp8131K$0.02$0.09$0.009—95.02%
ZDR: No

Training: Unknown

Prompt logging: Unknown

Retention: Unknown

Checked 2026-10-15

Darkbloomdarkbloom/fp8Batch pricing131K$0.02$0.09$0.009—95.02%
ZDR: No

Training: Unknown

Prompt logging: Unknown

Retention: Unknown

Checked 2026-10-15

AkashMLakashml/fp4131K$0.02$0.10——100.00%
ZDR: Yes

Training: Unknown

Prompt logging: Unknown

Retention: Unknown

Checked 2026-10-15

AkashMLakashml/fp4Batch pricing131K$0.02$0.10——100.00%
ZDR: No

Training: Unknown

Prompt logging: Unknown

Retention: Unknown

Checked 2026-10-15

DekaLLMdekallm/bf16131K$0.03$0.14$0.03—100.00%
ZDR: Yes

Training: Unknown

Prompt logging: Unknown

Retention: Unknown

Checked 2026-10-15

DekaLLMdekallm/bf16Batch pricing131K$0.03$0.14$0.03—100.00%
ZDR: No

Training: Unknown

Prompt logging: Unknown

Retention: Unknown

Checked 2026-10-15

CoreWeavecoreweave/fp4131K$0.03$0.13$0.03—100.00%
ZDR: Yes

Training: Unknown

Prompt logging: Unknown

Retention: Unknown

Checked 2026-10-15

CoreWeavecoreweave/fp4Batch pricing131K$0.03$0.13$0.03—100.00%
ZDR: No

Training: Unknown

Prompt logging: Unknown

Retention: Unknown

Checked 2026-10-15

DeepInfradeepinfra/bf16131K$0.03$0.14——99.70%
ZDR: Yes

Training: Unknown

Prompt logging: Unknown

Retention: Unknown

Checked 2026-10-15

DeepInfradeepinfra/bf16Batch pricing131K$0.03$0.14——99.70%
ZDR: No

Training: Unknown

Prompt logging: Unknown

Retention: Unknown

Checked 2026-10-15

Parasailparasail/fp4131K$0.03$0.15$0.02—99.93%
ZDR: Yes

Training: Unknown

Prompt logging: Unknown

Retention: Unknown

Checked 2026-10-15

Parasailparasail/fp4Batch pricing131K$0.03$0.15$0.02—99.93%
ZDR: No

Training: Unknown

Prompt logging: Unknown

Retention: Unknown

Checked 2026-10-15

SiliconFlowsiliconflow/fp8131K$0.04$0.18——89.59%
ZDR: Yes

Training: Unknown

Prompt logging: Unknown

Retention: Unknown

Checked 2026-10-15

SiliconFlowsiliconflow/fp8Batch pricing131K$0.04$0.18——88.47%
ZDR: No

Training: Unknown

Prompt logging: Unknown

Retention: Unknown

Checked 2026-10-15

Amazon Bedrockamazon-bedrock/eu-west-1131K$0.07$0.15——100.00%
ZDR: Yes

Training: Unknown

Prompt logging: Unknown

Retention: Unknown

Checked 2026-10-15

Amazon Bedrockamazon-bedrock131K$0.07$0.15——100.00%
ZDR: Yes

Training: Unknown

Prompt logging: Unknown

Retention: Unknown

Checked 2026-10-15

Amazon Bedrockamazon-bedrock/eu-west-1Batch pricing131K$0.07$0.15——100.00%
ZDR: No

Training: Unknown

Prompt logging: Unknown

Retention: Unknown

Checked 2026-10-15

Amazon Bedrockamazon-bedrockBatch pricing131K$0.07$0.15——100.00%
ZDR: No

Training: Unknown

Prompt logging: Unknown

Retention: Unknown

Checked 2026-10-15

Googlegoogle-vertex/us-central1131K$0.07$0.25——98.89%
ZDR: Yes

Training: Unknown

Prompt logging: Unknown

Retention: Unknown

Checked 2026-10-15

Googlegoogle-vertex/us-central1Batch pricing131K$0.07$0.25——99.29%
ZDR: No

Training: Unknown

Prompt logging: Unknown

Retention: Unknown

Checked 2026-10-15

Groqgroq131K$0.08$0.30$0.04—99.93%
ZDR: Yes

Training: Unknown

Prompt logging: Unknown

Retention: Unknown

Checked 2026-10-15

GroqgroqBatch pricing131K$0.08$0.30$0.04—99.86%
ZDR: No

Training: Unknown

Prompt logging: Unknown

Retention: Unknown

Checked 2026-10-15

Provider data:OpenRouter

Text provenance

EU · product-scoped

OpenAI textGrain watermarking

In the EU, ChatGPT-generated text uses textGrain. OpenAI says API customers can opt in globally for select models, so watermarking depends on the product surface and configuration.

Official explanation

Deployment graph

Can I run this?

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