Skip to main content
Frontend Glossary

Frontend engineering · Performance

Code Splitting

Also called: Split chunks, Breaking up the bundle, Route-based splitting

Split the build into smaller files loaded by route or component so the first visit doesn't download the entire app JS.

In detail

Without splitting, the home page may download a charting library only used in admin reports. With splitting, home gets the home chunk; opening Reports fetches that chunk later.

Framework route-level lazy loading and import() create split points. Too fine means too many requests; too coarse means little gain—use a bundle analyzer.

It pairs with Lazy Loading: splitting decides how files are cut; lazy loading decides when to fetch them.

Developer info
Term ID
eng-code-splitting
DOM selectors
No DOM cues. This concept isn't detected directly on a page.
Priority
1 · when several match at the same level, the higher priority wins
Version
v1 · updated Oct 5, 2026