Performance Tools
Browser-native inspectors and interactive testing tools for Performance. 100% client-side execution â zero external libraries.
Performance API
High-resolution millisecond timestamp measurement using performance.now().
Performance Observer
Observe real-time metric entries (paint, layout-shift, resource) as they occur.
Navigation Timing API
Inspect document load timing milestones (DNS, connect, DOMContentLoaded, load).
Resource Timing API
Detailed network fetch duration metrics for page resources (scripts, images, css).
Paint Timing API
Measure First Paint (FP) and First Contentful Paint (FCP) metrics.
Long Tasks API
Detect UI main-thread execution tasks that exceed 50 milliseconds.
User Timing API
Create custom application performance benchmarks using performance.mark and measure.
Scheduler API
Prioritize task execution queues using scheduler.postTask with user-blocking or background priorities.