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    SiLU / Swish

    AI fundamentals & modelsSigmoid Linear UnitSwish
    Reading time: 2 min.Editorially reviewed on:

    Definition

    SiLU and Swish are smooth activation functions for processing values in neural networks.

    A smooth, non-monotonic activation function f(x)=x·sigmoid(x). This function is called SiLU and corresponds to Swish with fixed parameter β=1; the general Swish family can use other β values.

    Simply explained

    Like a continuously variable controller, they change how strongly a number is passed on to the next processing layer.

    Why it matters in practice

    The term helps to select, develop, evaluate AI systems in a well-founded manner and realistically assess their technical risks.

    Example from business

    A neural network replaces ReLU with SiLU in its hidden layers.

    Limits and pitfalls

    • Equating SiLU with every parameterized Swish variant, interpreting the name as a different function, or claiming general superiority over ReLU or GELU.

    Origin & history

    Elfwing and co-authors described SiLU in 2017; Ramachandran and co-authors also studied and popularized Swish in 2017.

    Use in mid-sized companies

    • Possible application: A neural network replaces ReLU with SiLU in its hidden layers.

    Frequently asked questions

    What does SiLU / Swish mean?

    A smooth, non-monotonic activation function f(x)=x·sigmoid(x). This function is called SiLU and corresponds to Swish with fixed parameter β=1; the general Swish family can use other β values. What mistakes should be avoided? Equating SiLU with every parameterized Swish variant, interpreting the name as a different function, or claiming general superiority over ReLU or GELU.

    Sources

    Source checked on 10.10.2026. Editorial application examples are hypothetical; no proof of real customer results.

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