Browser-local tool

Performance Lab.

Estimate a first page budget, save an audit brief and carry it into the contact form. Nothing is transmitted.

Page-weight budget

No saved brief

Audit readiness

Before tracing

A primary task is named The likely LCP element is known Images reserve intrinsic space Third parties have owners A JavaScript budget exists Reduced motion is tested An error and rollback signal exists Field comparison uses the same population

This calculator is a planning aid, not a guarantee of Core Web Vitals, capacity, accessibility or business results. Test with your actual routes and audience.