# Local, synchronous evaluation

SDKs evaluate flags locally, synchronously, in memory with no network latency. This includes flag logic that contains experiments.

So you can use an SDK on the backend to evaluate flags, including experiments, for different users without adding latency to every request.

And you can use an SDK on the frontend to evaluate flags, including experiments, without blocking renders.


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Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.