Klein 9B is worth comparing with 4B when local image editing leaves too much correction work. Its larger weights bring higher memory demands, and the FLUX Non-Commercial License limits how you can run or adapt them. Choose the distilled checkpoint for inference or Base for customization. Test both sizes on the same approved reference sheet and difficult poses; move to 9B only if the results justify the extra compute and licensing costs. Its A tier depends on a permitted deployment. Keep the license's limits on model operation, training and derivatives separate from its permission to use outputs commercially.
Commercial use & license
Open weights under the FLUX Non-Commercial License. Commercial or production operation and commercial fine-tuning require separate terms. The license permits commercial use of outputs under its conditions; that permission does not cover commercial operation of the model.
Adult content rules
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What you need
A compatible GPU runtime, model components and enough storage. Measure memory use in the workflow you plan to run.
Ranks are recommendations for the task described, based on reviewed documentation. Model ranks cover non-explicit development work. We have not run practical benchmarks. Check content policies and commercial terms separately. How the ranks work →
Sources & further reading +
Last checked 5 October 2026.