Next.js ships a bundle-optimizer agent and Bundle Analyzer tools

Shipped October 28: Next.js published the next-bundle-optimizer agent skill and a set of new Bundle Analyzer tools. Two doors into the same job: let an agent grind through your bundle report, or open the tools yourself and read where the bytes go.

Why JavaScript size is the metric that ages fastest

• Bundles grow quietly: every dependency bump and feature ships a few more bytes, and nobody sees it in review.
• The analyzer tools make the invisible visible: which pages pull which code, before a visitor pays for it on a phone.
• The agent skill takes the drudgery part: reading manifests, tracking chunks, proposing cuts. Judgement stays yours.

Every kilobyte of JavaScript is a tax every visitor pays on every visit. Tools that make the tax visible are gacor.

Static sites get this almost for free, which is why we like the pattern: this site ships one shared hydrate script and defers it until after first paint, measured with Lighthouse after every build. If you run a Next app, the October 28 tools make the same reasoning mechanical instead of vibes-based.