TypeScript Just Got 10x Faster! (Or Did It?)

The announcement that TypeScript is getting 10x faster is an exciting and significant step forward for the TypeScript ecosystem. The improvements in compilation speed, editor responsiveness, and reduced memory usage will greatly enhance the developer experience, especially for large projects. However, it’s important to clarify that this speed increase applies specifically to the TypeScript compiler and build times, not to the runtime performance of the generated JavaScript code. Since TypeScript ultimately compiles down to JavaScript, the execution speed of the final code remains unchanged.

This is an important distinction because when we hear about a programming language becoming “10x faster,” we typically assume it means fundamental optimizations to the language itself. For example, if an announcement claimed that “Java is getting 10x faster,” most developers would expect deep improvements at the runtime level – such as JIT compiler enhancements, better garbage collection, or low-level optimizations in the JVM – that directly make Java applications execute significantly faster.

In contrast, TypeScript’s improvements benefit developers primarily during the development process, making builds and editor interactions much faster. While this is fantastic news for developer productivity, the claim of “10x faster” should be understood in the context of tooling and compilation speed, rather than application performance at runtime.

To be clear, this is not meant to downplay the announcement – these improvements are a great step forward for the TypeScript ecosystem. The goal here is simply to clarify the slightly misleading title and ensure that expectations align with what’s actually changing.

Source: https://devblogs.microsoft.com/typescript/typescript-native-port/