Open model

An open model is a model for which selected artifacts and usage rights are made publicly available, with the degree of openness stated explicitly.

Plan for this page

Understand one concept in plain language and connect it to nearby ideas.

You will leave with: Possible artifacts include weights, architecture, inference code, training code, data information, evaluation, and documentation. A model can be open in some dimensions and closed in others, and license restrictions may differ from standard open-source software.
Time: 3–8 min
Before you begin: No prerequisite. Keep one real example in mind.
Do this now: Read the explanation, then compare the example with the common misunderstanding.

Prepared next stepCompare model access and control

Open modelAn open model is a model for which selected artifacts and usage rights are made publicly available, with the degree of openness stated explicitly.

Model card
Open source
Closed model

Plain explanation

Possible artifacts include weights, architecture, inference code, training code, data information, evaluation, and documentation. A model can be open in some dimensions and closed in others, and license restrictions may differ from standard open-source software.

Example

A developer releases model weights and inference code with a license and model card but does not release the complete training dataset.

Why it matters

Open access can support study, adaptation, local operation, competition, and auditing while also changing misuse and support risks. Compare concrete artifacts and rights rather than relying on the label.

Common misunderstanding

Misconception: open model always means every dataset, method, weight, and right is unrestricted. Correction: openness is layered and must be read item by item.

Related concepts

Follow relationships, not only the alphabet

Model cardA model card is structured documentation describing a model’s intended uses, evaluation, limitations, development context, and relevant risks.Open sourceOpen source describes software whose source code is available under a license granting defined rights to use, inspect, modify, and redistribute it.Closed modelA closed model is a model whose key artifacts, internal details, or operating access are not publicly released beyond provider-defined interfaces and terms.

Compare model access and control

Sources and scope

What supports this object

Stanford AI Index Report 2026Stanford Institute for Human-Centered AI

Reports on evolving model ecosystems and access; “open model” remains multidimensional, so weights, code, data, documentation and license must be described separately.

Open source

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