If an error is detected in a file but no one sees it, is it really highlighted? This is a tale about why highlighting only what’s visible is both the strangest and the most reasonable thing to do – a

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The IntelliJ Scala Plugin now offers an 'Incremental Highlighting' mode that limits code analysis to the visible area of the editor rather than the entire file. This approach reduces CPU, RAM, and battery usage while improving IDE responsiveness — with highlighting times potentially reduced by 5–10x for large or complex Scala files. The mode caches already-highlighted regions, pre-highlights 15 lines around the visible area for smooth scrolling, and supports split editors and diff viewers. Some inspections like 'Unused Declaration' are disabled in this mode, but the full file can still be analyzed on demand by double-pressing Esc. The feature is enabled via Settings | Scala | Editor | Highlighting Mode | Incremental and is per-project.

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