“Next.js 15” has finally been released in beta with the recent update, and is causing a lot of excitement in the front-end world. I also immediately upgraded my personal project from Next.js 14 to 15 and tried out some new features. In this article, I will provide a review of the ``amazing evolution’’ that I felt after actually touching it.

The evolution of Next.js 15 that surprised me when I touched it

If I had to describe it in one word, it would be “the ultimate improvement in developer experience (DX) and performance.” Next.js has been in the middle of a major paradigm shift since App Router was introduced, and version 15 feels like it’s nearing completion.

1. Free yourself from manual memoization with React Compiler

Personally, what impressed me the most was the official support for React Compiler. Previously, you had to write useMemo, useCallback, and React.memo everywhere to prevent unnecessary re-rendering. However, with Next.js 15, the compiler will do the optimization for you.

I actually tried removing all of these hooks from my code, and it didn’t slow things down at all, but instead made my code base dramatically cleaner. This alone is worth the move.

2. Revision of default cache strategy

In previous versions, many developers were confused by the aggressive specification of ``caching everything by default’’ (I was one of them). In Next.js 15, the default for fetch requests (fetch) has been revised to no-store, and we have returned to an opt-in method where you explicitly specify only the parts that need caching. This reduces the number of unintentional stale data displays and makes intuitive development possible again.

3. Explosive startup speed due to Turbopack stabilization

The speed at which the local development environment can be set up is also noteworthy. Turbopack, a Rust-based bundler, is now even more stable, allowing servers to start up in literally an instant, even for large projects. The response of hot reload (Fast Refresh) was also overwhelming, and the stress caused by waiting time was almost eliminated.

Overall review: Should you migrate now?

In conclusion, if it’s a new project, we recommend building it on Next.js 15 (or React 19) without hesitation. Even if you have an existing project, if you have already migrated to App Router, the hurdles to upgrading it will not be that high.

“Fast” doesn’t just refer to the browser’s drawing speed. This means the entire cycle for developers to write, review, and deploy code is faster. I feel that Next.js 15 is the culmination of a framework that can achieve this “blazingly fast cycle.”