Performance100% Free UtilityOpen-Source CLI

PayloadSniper INP & Script Bloat-Tracer

Analyzes main-thread execution timelines to identify scripts degrading Interaction to Next Paint (INP) and Total Blocking Time (TBT). Maps blocking durations to third-party marketing vendors.

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What This Metric Means for Your Site

Interaction to Next Paint measures page responsiveness to user input. Unoptimized hydration bundles and heavy third-party marketing tags freeze the main thread, causing noticeable input delays.

How to Improve Your Score (Actionable Fixes)

  • Add defer or async attributes to external head scripts to unblock First Contentful Paint.
  • Break up monolithic execution blocks exceeding 50ms using scheduler.yield() or requestIdleCallback().
  • Offload non-critical third-party trackers (GTM, Meta Pixel, Hotjar) via web workers or delayed hydration.
  • Audit bundle splits with dynamic imports to defer JavaScript needed only on user interaction.
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Authoritative Specification & Source

PayloadSniper INP & Script Bloat-Tracer Open Source Engine

View the headless CLI implementation and inspect the source code on GitHub.

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