WebPerf

Real-time website performance analyzer — measures Core Web Vitals, network waterfall, code coverage, critical rendering path, third-party impact, SEO, accessibility, WCAG compliance, and more from your terminal.

Features

WebPerf runs 15 probes against any URL and produces an actionable performance report:

| Probe | What it measures | |-------|-----------------| | Network | DNS, TCP, TLS, TTFB, headers, compression, HTTP/2+ | | Browser | Core Web Vitals (LCP, FID, CLS, INP, FCP, TTFB) via headless Chrome | | Resource | Asset breakdown by type, size, cacheability | | Server | Response codes, redirect chains, server timing | | Critical Path | Render-blocking resources, critical request depth | | Waterfall | Full request waterfall with timing breakdown | | Coverage | Unused CSS/JS bytes and percentage | | Third-Party | External script impact on main thread | | SEO | Meta tags, structured data, Open Graph, robots | | Accessibility | ARIA, color contrast, landmark roles, alt text | | WCAG | Full WCAG 2.1 compliance audit (A / AA / AAA) | | Flutter | Flutter Web-specific metrics (auto-detected) | | Lighthouse | Side-by-side comparison with Google Lighthouse | | Geo | Simulated latency from multiple regions | | Screenshots | Page lifecycle screenshots (blank → FCP → loaded) |

Additional capabilities

• HTML reports — beautiful self-contained HTML report (--format html)
• A/B comparison — compare two URLs head-to-head (--ab <url>)
• Performance budgets — fail CI if score drops below threshold (--budget 80)
• Crawl mode — follow internal links and analyze multiple pages (--crawl)
• Network throttling — simulate slow3g, fast3g, 4g, cable (--throttle slow3g)
• Watch mode — live dashboard that re-runs every N seconds (--watch 30)
• History tracking — track performance over time (--history)
• AI recommendations — Claude-powered analysis (--ai)
• Config file — reusable settings via webperf.toml

Install

Homebrew (macOS)

brew tap ff-vivek/tap
brew install webperf

GitHub Releases

Download the latest binary from Releases.

# macOS universal binary
curl -L https://github.com/ff-vivek/webperf-cli/releases/latest/download/webperf-macos-universal.tar.gz | tar xz
sudo mv webperf /usr/local/bin/

From source

git clone https://github.com/ff-vivek/webperf-cli.git
cd webperf-cli
cargo build --release
cp target/release/webperf /usr/local/bin/

Usage

# Basic analysis
webperf https://example.com

# JSON output
webperf https://example.com --json

# HTML report
webperf https://example.com --format html --output report.html

# Run specific probes only
webperf https://example.com --probes network,browser,seo,accessibility

# Performance budget (CI-friendly, exits 1 if below threshold)
webperf https://example.com --budget 80

# A/B comparison
webperf https://example.com --ab https://staging.example.com --iterations 5

# Crawl mode
webperf https://example.com --crawl --depth 2 --max-pages 5

# Simulate geographic regions
webperf https://example.com --region eu-west,ap-south

# Network throttling
webperf https://example.com --throttle slow3g

# Watch mode (re-run every 30s)
webperf https://example.com --watch 30

# WCAG compliance audit
webperf https://example.com --wcag aaa

# AI-powered recommendations (requires ANTHROPIC_API_KEY)
webperf https://example.com --ai

# Config file
webperf https://example.com --config ./webperf.toml

Desktop App

WebPerf also ships as a macOS desktop app built with Flutter, providing a visual interface for running analyses and viewing results.

Download the latest DMG from Releases.

See the webperf_app/ directory for the desktop app source.

Screenshots

See the screenshots/ directory.

Roadmap

See ROADMAP.md for planned features and future direction.

License

MIT — Copyright (c) 2026 Vivek Yadav