How Swiss tables work in Go built-in map
This article explains the technical transition of Go's built-in map implementation to Swiss Tables. It provides a visual and conceptual breakdown of how the Go runtime manages memory and key-value storage.
Why it matters
Understanding runtime internals helps developers write more efficient code and debug performance bottlenecks in high-scale Go applications.
We have already written about Go maps and their old runtime implementation in Go Maps Explained: How Key-Value Pairs Are Actually Stored . Go 1.24 replaced that implementation with a design based on Swiss Tables, so it is time for an update.
You do not need to go back and read the old article. We will review how maps behave and the concepts needed here before moving into the new runtime internals.
The Go blog also has an excellent article, Faster Go maps with Swiss Tables . It goes deeper and assumes a little more background knowledge. We take a different approach. We will discuss the same implementation more gradually and in a visual way, so you can relax your brain a little and still understand what Go is doing.
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