Why is it important to remove unused code?
Removing unused code matters because it directly hurts a site's speed, size, and stability, even if it "seems harmless".
1. Increases bundle weight
Every extra byte is extra loading, especially on mobile and slow networks. More code means a longer wait.
2. Slows down parsing and execution
JS first has to be loaded, parsed, compiled, and executed. Even if code is never used, it still goes through these steps.
3. Clogs the cache and memory
Unnecessary code can end up in the browser cache, take up memory, and affect GC (garbage collection), especially in SPAs.
4. Makes maintenance harder
Dead code gets in the way of navigating the project, creates noise, confuses people, and can cause side effects (if it has global calls, imports, or side effects).
5. Affects Web Vitals
More scripts mean worse LCP, TTI, TBT, and therefore worse SEO and UX.
Conclusion: Removing unused code is not about aesthetics, it's optimization: less to load, faster to run, easier to maintain.
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