Runtime, memory & payload10 problems
Performance
Runtime problems that make an AI-built page slow, janky, or heavy — DOM bloat, memory leaks, layout shift, long tasks, oversized images and bundles. Each one is caught live by a VibeCheck detector as it happens in the browser.
Caught by the dom-bloat, memory-leak, layout-thrashing, long-task, image, resource and heavy-library detectors.
- Excessive DOM sizeerrorA huge DOM slows style, layout and memory on every frame. Virtualize long lists and flatten wrappers to get node count back under control.
- JavaScript memory leakerrorA leaking heap grows until the tab janks or crashes. Find the listeners, timers and subscriptions that are never cleaned up and release them.
- Cumulative layout shift (CLS)warningContent that jumps as the page loads fails Core Web Vitals and mis-taps users. Reserve space for images, ads and late content to stop the shift.
- Long tasks blocking the main threadwarningLong tasks freeze the page and wreck INP. Break up heavy work, defer it, or move it to a worker so the main thread stays responsive to input.
- Console.log spamwarningDebug logs left in production leak internals, slow hot paths, and bury real errors. Strip them at build time and add a no-console lint rule.
- Duplicate network requestswarningThe same endpoint fetched several times wastes bandwidth and risks race conditions. Deduplicate with a query cache or a shared in-flight request.
- Unoptimized imageserrorImages without dimensions shift layout; oversized ones waste bandwidth. Add width/height, lazy-load below the fold, and serve the right size.
- Large image fileserrorMulti-hundred-KB images blow your LCP and mobile data budget. Compress to WebP/AVIF, resize to display size, and serve from an image CDN.
- Large JavaScript bundleswarningOversized JS bundles delay interactivity and waste mobile data. Code-split by route, tree-shake imports, and lazy-load heavy components.
- Heavy dependencieswarningHeavy libraries add weight and known pitfalls. Lazy-load them, import a lighter subset, or swap for a native API to cut bundle size and jank.