Measure the time taken to paint the first important element.

UptimeMesh web analytics & monitoring SDK — sessions, errors, network, Web Vitals, frustration signals, privacy masking, real-time heartbeat

Web performance metric collector

client-side js library

ElysiaJS middleware exporting HTTP request duration metrics

Typed, zero-dependency E2E client and CLI for driving live JUCE WebViews over a debug-only loopback bridge, without CDP.

An API that provides a way to asynchronously observe the connectedness of a target Node or querySelector inside a document

In-browser collector SDK for AgentLens — captures errors, console and network signals during development.

Get performance measurements from React Fiber

Multi-platform UI/mobile automation for AI agents — MCP server + shipped skills.

The package for measuring the element timing is more simple

Library for measuring client performance metrics

前端性能监控,采集以及上报。用于测量第一个dom生成的时间(FP/FCP/LCP)、用户最早可操作时间（fid|tti）和组件的生命周期性能,，网络状况以及资源大小等等。向监控后台报告实际用户测量值。

ESLint rules that enforce the NoMercy player-trio v2 code standard.

Lightweight, zero-dependency Express middleware for server latency profiling — p50/p95/p99, slow-request capture, event-loop lag, GC tracking.

Write performance measurements from oneRepo invocations to files.

前端性能分析，主要基于performance获取各项指标数据

tiny js/css/img loading library

A zero-impact browser telemetry tracker for network bloat, CPU long tasks, and OLED display luminance.

This library aims to provide an `observable` based API, that wraps the web APIapi. This also includes experimental, non-standard and not well-supported APIs. Polyfills need to be provided by the user of this library if necessary.