Mobile Overflow & Viewport Breakage Tracer
Simulates mobile viewports (iPhone SE 375px, compact 320px) to identify elements exceeding viewport bounds, isolate rogue 100vw offsets, and provide drop-in CSS remediation.
What This Metric Means for Your Site
Elements exceeding mobile screen widths trigger horizontal scrolling, disrupting touch navigation and causing mobile usability penalties in Google Search Console.
How to Improve Your Score (Actionable Fixes)
- Replace 'width: 100vw' with 'width: 100%' to prevent scrollbar gutter width offset bugs.
- Apply 'min-width: 0' on flex children to allow text and code snippets to shrink inside rows.
- Wrap data tables and code blocks in dedicated containers with 'overflow-x: auto'.
- Apply 'overflow-x: clip' to root HTML/body containers to contain layouts without breaking sticky positioning.
Zero CLS Web Design: How to Diagnose and Prevent Layout Shifts
Cumulative Layout Shift degrades user experience and lowers Core Web Vitals pass rates. Learn how aspect ratio containers, font fallback overrides, and fluid clamp typography prevent sudden visual jumps on mobile devices.
LCP Element Finder
Isolate the exact DOM element and image asset triggering your Largest Contentful Paint.
Mobile Overflow & Viewport Breakage Tracer Open Source Engine
View the headless CLI implementation and inspect the source code on GitHub.
VitalsSniper PRO In-Tab Forensics
Isolate exact DOM elements, generate white label PDF audit summaries, and export outreach lead lists in 50ms from any live Chromium tab.