You can download an AI model’s weights. What does that actually let you do?

A downloadable file establishes availability of that file. Check the terms and supporting materials before assuming you can inspect, modify or redistribute the whole system.

Our view: “open” is useful only when you say what is available and what the recipient may do. A model’s weights are learned parameters; having them is a different question from having the training code, data information or permission for a particular use.

Use a named definition when making a claim

The Open Source Initiative’s Open Source AI Definition 1.0 calls for freedoms to use, study, modify and share, along with data information, code and parameters needed for modification. Its data-information requirement should not be shortened to a claim that every original training item must be downloadable.

Read the actual release

Our proposed checklist is to record which weights, inference code, training code and data descriptions are supplied, and where their terms are stated. If one item is missing, mark it missing instead of letting the headline “open model” fill the gap.

A useful release can still have limits

A downloadable model may help someone run or investigate a system, subject to its requirements and terms. That practical value does not by itself establish complete reproducibility, unrestricted redistribution, or safety for a particular deployment. These are separate questions requiring their own evidence.

Make the decision specific

For a project, ask whether the supplied materials and terms support the use, modification and sharing you actually intend. OSI’s definition is one explicit framework, not a finding about every model advertised as open. We have not assessed or certified a named model here.

Published October 14, 2026. This is an editorial interpretation of an existing definition, not a new release or legal determination. No model download, training reproduction, deployment or license audit was performed.

Sources: OSI · Open Source AI Definition.