LLM Reference

OLMo Models by Allen Institute for Artificial Intelligence (AI2)

6 models2024–2026Up to 64k ctxFrom $0.2/1M input

Last refreshed 2026-04-27. Next refresh: weekly.

Details

LicenseApache 2.0OSI-approved
Commercial useCommercial use: permitted
Models6
Released2024–2026
Max context64k

Capabilities

Reasoning1 of 6 models
JSON / Tool use1 of 6 models
Structured Outputs4 of 6 models

About

The OLMo family of large language models (LLMs) is a series of open-source models developed by the Allen Institute for Artificial Intelligence (AI2) to advance the science of language modeling. These models stand out for their openness, offering researchers access to the training data, code, models, and evaluation resources. This transparency helps examine various aspects of LLM development, including biases and risks. Trained on the Dolma dataset, OLMo models utilize the Tulu SFT mixture and a refined UltraFeedback dataset for enhanced question answering. The family includes different models with varying parameters, such as 1B and 7B, reflecting distinct training phases and optimizations, and encourages collaborative research within the open-source AI community 123.

Decision facts

Best fit
reasoningJSON / Tool usestructured outputs
Capability starting point
OLMo 3.1 32B Instruct with 64k context and JSON / Tool use and structured outputs
Lowest tracked input
OLMo 7B · $0.2/1M · Together AI
Closest related family
Tulu

Current Variants

Use-when guidance is based on each model's tracked capabilities, context window, release date, and replacement status.

6 in view

Use when the workload needs 64k context, 32B parameters, and reasoning.

2026-0364k context32B parametersreasoning

Use when the workload needs 64k context, 32B parameters, and JSON / Tool use.

2026-0264k context32B parametersJSON / Tool use
OLMo 7BCurrent

Use when the workload needs 7B parameters and structured outputs.

2024-027B parametersstructured outputs
OLMo 1BCurrent

Use when the workload needs 1B parameters and structured outputs.

2024-021B parametersstructured outputs

Use when the workload needs 7B parameters and structured outputs.

2024-027B parametersstructured outputs

Use when the workload needs 7B parameters.

2024-027B parameters

Release Timeline

3 release groups
2026-03
1 current
OLMo 3 32B Think
64k context32B parametersreasoning
Current
2026-02
1 current
OLMo 3.1 32B Instruct
64k context32B parametersJSON / Tool use
Current
2024-02
4 current
OLMo 1.7 7B
7B parameters
Current
OLMo 1B
1B parametersstructured outputs
Current
OLMo 7B
7B parametersstructured outputs
Current
OLMo 7B Twin-2T
7B parametersstructured outputs
Current

Specifications(6 models)

OLMo model specifications comparison
ModelReleasedContextParametersReasoningJSON / Tool useStructured Outputs
OLMo 3 32B Think2026-0364k32BYesNoNo
OLMo 3.1 32B Instruct2026-0264k32BNoYesYes
OLMo 7B2024-027BNoNoYes
OLMo 1B2024-021BNoNoYes
OLMo 7B Twin-2T2024-027BNoNoYes
OLMo 1.7 7B2024-027BNoNoNo

Available From(3 providers)

Pricing

OLMo model pricing by provider
ModelProviderInput / 1MOutput / 1MType
OLMo 7BTogether AI$0.2$0.2Serverless
OLMo 7B Twin-2TTogether AI$0.2$0.2Serverless
OLMo 1BOpenRouter$15$60Serverless