web-perf

Node.js CLI and library for web performance auditing. Analyze any website using local Lighthouse audits, real-user metrics from PageSpeed Insights, Chrome UX Report data via the CrUX API, or extract URLs from sitemaps and rendered pages.

Requirements

Node.js >= 18
Google Chrome installed locally (required for lab and links)
Google Cloud API key with PageSpeed Insights API and/or CrUX API enabled (required for psi, crux, crux-history) — pass inline with --api-key, via a file with --api-key-path, or set WEB_PERF_PSI_API_KEY (key) or WEB_PERF_PSI_API_KEY_PATH (file path) environment variable

Quick Start

# Local Lighthouse audit
web-perf lab https://example.com

# PageSpeed Insights (real-user data)
web-perf psi --api-key=<YOUR_KEY> https://example.com

# CrUX data (28-day rolling average)
web-perf crux --api-key=<YOUR_KEY> https://example.com

# Historical CrUX trends (~6 months)
web-perf crux-history --api-key=<YOUR_KEY> https://example.com

Google Cloud API key (for `psi`, `crux`, `crux-history`)

Create an API key in the Google Cloud Console under APIs & Services > Credentials, with the following APIs enabled:

PageSpeed Insights API — required for psi
Chrome UX Report API — required for crux and crux-history

Note: After enabling the Chrome UX Report API, it may take a few minutes for the API key to become effective.

# Inline
web-perf psi --api-key=<YOUR_KEY> <url>
web-perf crux --api-key=<YOUR_KEY> <url>

# From file (plain text, key only)
web-perf psi --api-key-path=<path-to-file> <url>

# Via environment variable (inline key)
export WEB_PERF_PSI_API_KEY=<YOUR_KEY>
web-perf psi <url>

# Via environment variable (file path)
export WEB_PERF_PSI_API_KEY_PATH=<path-to-key-file>
web-perf crux <url>

CLI Usage

web-perf <command> [options] <url>

Available commands: lab, psi, crux, crux-history, links, sitemap, list-profiles, list-networks, list-devices.

Command	Source	Result	Options
`lab`	Local Lighthouse audit (headless Chrome)	JSON report with performance scores and Web Vitals	`--profile`, `--network`, `--device`, `--urls`, `--urls-file`, `--skip-audits`, `--blocked-url-patterns`, `--no-strip-json-props`
`psi`	PageSpeed Insights API (real-user data + Lighthouse)	JSON with field metrics and lab scores	`--api-key`, `--api-key-path`, `--urls`, `--urls-file`, `--category`, `--concurrency`, `--delay`
`crux`	CrUX API (origin or page, 28-day rolling average)	JSON with p75 Web Vitals and metric distributions	`--scope`, `--api-key`, `--api-key-path`, `--urls`, `--urls-file`, `--concurrency`, `--delay`
`crux-history`	CrUX History API (~6 months of weekly data points)	JSON with historical Web Vitals over time	`--scope`, `--api-key`, `--api-key-path`, `--urls`, `--urls-file`, `--concurrency`, `--delay`
`sitemap`	Domain's `sitemap.xml` (recursive, auto-detects sitemap URLs)	JSON list of all URLs found	`--depth`, `--delay`, `--output-ai`
`links`	Rendered DOM via headless Chrome (SPA-compatible)	JSON list of internal links	`--output-ai`
`list-profiles`	—	Prints available simulation profiles	—
`list-networks`	—	Prints available network presets	—
`list-devices`	—	Prints available device presets	—

Commands

`lab` — Local Lighthouse audit

Runs a full Lighthouse audit in headless Chrome and saves the JSON report. Supports simulation profiles to test under different device and network conditions.

# Default (Lighthouse defaults: Moto G Power on Slow 4G)
web-perf lab <url>

# Single profile
web-perf lab --profile=low <url>
web-perf lab --profile=high <url>

# Multiple profiles (comma-separated)
web-perf lab --profile=low,high <url>

# All profiles (low, medium, high)
web-perf lab --profile=all <url>

# Granular control
web-perf lab --network=3g --device=iphone-12 <url>

# Profile with partial override (low device + wifi network)
web-perf lab --profile=low --network=wifi <url>

# Skip specific audits
web-perf lab --skip-audits=full-page-screenshot,screenshot-thumbnails <url>

# Block URL patterns (prevent asset downloads during audit, e.g. analytics, ads)
web-perf lab --blocked-url-patterns='*.google-analytics.com,*.facebook.net' <url>
web-perf lab --profile=low --blocked-url-patterns='*.ads.example.com' <url>

# Strip unneeded properties (i18n, timing) from JSON output (default: enabled)
web-perf lab --profile=low <url>  # JSON excludes i18n, timing
web-perf lab --no-strip-json-props <url>  # JSON includes all properties (raw Lighthouse output)

# Multiple URLs (<url> argument is ignored when --urls or --urls-file is provided)
web-perf lab --urls=<url1>,<url2> --profile=low
web-perf lab --urls-file=<urls.txt> --profile=all

Parameter	Required	Description
`<url>`	Yes*	Full URL to audit (e.g. `https://example.com`). Ignored when `--urls` or `--urls-file` is provided
`--profile <preset>`	No	Simulation profile(s): `low`, `medium`, `high`, `native`, `all` (comma-separated)
`--network <preset>`	No	Network throttling: `3g-slow`, `3g`, `4g`, `4g-fast`, `wifi`, `none`
`--device <preset>`	No	Device emulation: `moto-g-power`, `iphone-12`, `iphone-14`, `ipad`, `desktop`, `desktop-large`
`--urls <urls>`	No	Comma-separated list of URLs to audit
`--urls-file <path>`	No	Path to a file with one URL per line
`--skip-audits <audits>`	No	Comma-separated Lighthouse audits to skip. Default: `full-page-screenshot,screenshot-thumbnails,final-screenshot,valid-source-maps`
`--blocked-url-patterns <patterns>`	No	Comma-separated URL patterns to block during the audit (e.g. `.google-analytics.com,.facebook.net`). Uses Chrome DevTools Protocol to prevent matching assets from being downloaded
`--no-strip-json-props`	No	Disable stripping of unneeded properties (`i18n`, `timing`) from JSON output. Omit or leave blank to strip (default). See ADR-001 for rationale

Run list-profiles, list-networks, or list-devices to see all available presets:

Chrome must be installed on the machine.

Profiles

Profile	Device	Network	Description
`low`	Moto G Power	Regular 3G	Budget phone on 3G
`medium`	Moto G Power	Slow 4G	Lighthouse default
`high`	Desktop 1350x940	WiFi	Desktop on broadband
`native`	No emulation	No throttling	Actual device (no emulation, no throttling)

When --network or --device are used together with --profile, the granular flags override the corresponding part of the profile. For example, --profile=low --network=wifi keeps the Moto G Power device but switches the network to WiFi.

web-perf list-profiles
web-perf list-networks
web-perf list-devices

Output: results/lab/lab-<hostname>-YYYY-MM-DD-HHMM.json

`psi` — PageSpeed Insights (real-user data)

Fetches real-user metrics and Lighthouse results from the PageSpeed Insights API.

# Single URL with inline API key
web-perf psi --api-key=<PSI_KEY> <url>

# Single URL with API key from file (plain text, key only)
web-perf psi --api-key-path=<path-to-key-file> <url>

# Multiple URLs (comma-separated) — <url> argument is ignored if present
web-perf psi --urls=<url1>,<url2>,<url3> --api-key=<PSI_KEY>

# Multiple URLs from file (one URL per line) — <url> argument is ignored if present
web-perf psi --urls-file=<urls.txt> --api-key=<PSI_KEY>

# Parallel processing (10 concurrent requests, 100ms delay between each)
web-perf psi --urls-file=<urls.txt> --api-key=<PSI_KEY> --concurrency=10 --delay=100

Parameter	Required	Description
`<url>`	Yes*	Full URL to analyze (e.g. `https://example.com`)
`--api-key <key>`	No**	PageSpeed Insights API key passed inline
`--api-key-path <path>`	No**	Path to a plain text file containing only the API key
`--urls <list>`	No	Comma-separated list of URLs. When provided, `<url>` argument is ignored
`--urls-file <path>`	No	Path to a file with one URL per line. When provided, `<url>` argument is ignored
`--category <list>`	No	Comma-separated Lighthouse categories to include. Values: `performance`, `accessibility`, `best-practices`, `seo`. Default: all four
`--concurrency <n>`	No	Max parallel API requests when processing multiple URLs. Default: `5`
`--delay <ms>`	No	Delay in ms between requests per worker. Default: `0` (no delay)

Built-in quota protection: PSI request starts are capped at 4 requests/second globally during batch runs, regardless of --concurrency.

* Not required when --urls or --urls-file is provided. ** A PSI API key is required. Provide it via --api-key, --api-key-path, or the WEB_PERF_PSI_API_KEY / WEB_PERF_PSI_API_KEY_PATH environment variables. CLI flags take precedence.

# Only performance
web-perf psi --category=performance --api-key-path=<key-file> <url>

# Performance and SEO only
web-perf psi --category=performance,seo --api-key-path=<key-file> <url>

Credential resolution order

--api-key flag (inline key)
--api-key-path flag (file path)
WEB_PERF_PSI_API_KEY env var (inline key)
WEB_PERF_PSI_API_KEY_PATH env var (file path)
Interactive prompt

Output: results/psi/psi-<hostname>-YYYY-MM-DD-HHMM.json (one file per URL)

`crux` — CrUX data (28-day rolling average)

Queries Chrome UX Report data via the CrUX REST API. Returns a 28-day rolling average of Web Vitals metrics. Supports both origin-level and page-level queries via --scope. Pages need ~300+ monthly visits to have data.

# Origin-level (default)
web-perf crux --api-key=<KEY> <url>

# Page-level
web-perf crux --scope=page --api-key=<KEY> <url>

# Multiple URLs (page scope)
web-perf crux --urls=<url1>,<url2> --api-key=<KEY>
web-perf crux --urls-file=<urls.txt> --api-key=<KEY> --concurrency=10 --delay=100

Parameter	Required	Description
`<url>`	Yes*	URL or origin to query
`--scope <scope>`	No	Query scope: `origin` or `page`. Default is `origin` for single URL input, and `page` when using `--urls` or `--urls-file`
`--api-key <key>`	No**	CrUX API key
`--api-key-path <path>`	No**	Path to plain text file containing the API key
`--urls <urls>`	No	Comma-separated URLs (page scope)
`--urls-file <path>`	No	Path to file with one URL per line (page scope)
`--concurrency <n>`	No	Max parallel requests. Default: `5`
`--delay <ms>`	No	Delay between requests in ms. Default: `0`

Built-in quota protection: CrUX request starts are capped at 2.5 requests/second globally during batch runs, regardless of --concurrency.

* Not required when --urls or --urls-file is provided. ** A CrUX API key is required. Provide via --api-key, --api-key-path, or the WEB_PERF_PSI_API_KEY / WEB_PERF_PSI_API_KEY_PATH environment variables.

Output: results/crux/crux-<hostname>-YYYY-MM-DD-HHMM.json

`crux-history` — Historical CrUX data

Queries the CrUX History API for ~6 months of weekly data points. Each data point represents a 28-day rolling average. Supports both origin-level and page-level queries.

# Origin-level (default)
web-perf crux-history --api-key=<KEY> <url>

# Page-level
web-perf crux-history --scope=page --api-key=<KEY> <url>

# Multiple URLs (page scope)
web-perf crux-history --urls=<url1>,<url2> --api-key=<KEY>
web-perf crux-history --urls-file=<urls.txt> --api-key=<KEY> --concurrency=10 --delay=100

Parameter	Required	Description
`<url>`	Yes*	URL or origin to query (e.g. `https://example.com`)
`--scope <scope>`	No	Query scope: `origin` or `page`. Default is `origin` for single URL input, and `page` when using `--urls` or `--urls-file`
`--api-key <key>`	No**	CrUX API key
`--api-key-path <path>`	No**	Path to plain text file containing the API key
`--urls <urls>`	No	Comma-separated URLs (page scope)
`--urls-file <path>`	No	Path to file with one URL per line (page scope)
`--concurrency <n>`	No	Max parallel requests. Default: `5`
`--delay <ms>`	No	Delay between requests in ms. Default: `0`

Built-in quota protection: CrUX History request starts are capped at 2.5 requests/second globally during batch runs, regardless of --concurrency.

* Not required when --urls or --urls-file is provided. ** A CrUX API key is required. Credential resolution is identical to crux (see above).

Output: results/crux-history/crux-history-<hostname>-YYYY-MM-DD-HHMM.json

`sitemap` — Sitemap URL extraction

Parses a domain's sitemap.xml (including sitemap indexes) and extracts all URLs. Auto-detects if the URL points to a sitemap (.xml extension) or uses <url>/sitemap.xml by default.

web-perf sitemap <url>
web-perf sitemap --depth=3 <url>
web-perf sitemap https://example.com/custom-sitemap.xml
web-perf sitemap --output-ai <url>

Parameter	Required	Description
`<url>`	Yes	Domain or sitemap URL (e.g. `example.com` or `example.com/sitemap-pages.xml`)
`--depth <n>`	No	Max recursion depth for sitemap indexes. Default: `3`
`--delay <ms>`	No	Delay between requests in ms (randomized ±50ms). Default: `0`
`--output-ai`	No	Generate AI-friendly `.txt` output (one URL per line, normalized)

Output: results/sitemap/sitemap-<hostname>-YYYY-MM-DD-HHMM.json

`links` — Internal link extraction

Extracts internal links from the rendered DOM using headless Chrome. SPA-compatible (waits for JavaScript rendering).

web-perf links <url>
web-perf links --output-ai <url>

Parameter	Required	Description
`<url>`	Yes	URL to extract links from
`--output-ai`	No	Generate AI-friendly `.txt` output (one URL per line, normalized)

Output: results/links/links-<hostname>-YYYY-MM-DD-HHMM.json

Environment variables

Variable	Command	Description
`WEB_PERF_PSI_API_KEY`	`psi`, `crux`, `crux-history`	API key for PageSpeed Insights / CrUX API
`WEB_PERF_PSI_API_KEY_PATH`	`psi`, `crux`, `crux-history`	Path to file containing the API key

CLI flags (--api-key, --api-key-path) always take precedence over environment variables.

Output structure

All results are saved as JSON files under the results/ directory, organized by command:

results/
├── lab/
│   └── lab-example.com-2026-03-29-1430.json
├── psi/
│   └── psi-example.com-2026-03-29-1430.json
├── crux/
│   └── crux-www.example.com-2026-03-29-1430.json
├── crux-history/
│   └── crux-history-www.example.com-2026-03-29-1430.json
├── links/
│   └── links-www.example.com-2026-03-29-1430.json
└── sitemap/
    └── sitemap-www.example.com-2026-03-29-1430.json

Library API

web-perf can be used as a Node.js library. The pure audit functions return data directly — no files written, no disk I/O — making them safe for use in servers and backends.

// CommonJS
const { runCruxAudit, runPsiAudit, runLabAudit } = require('web-perf');

// Subpath imports (load only what you need)
const { runCruxAudit, runCruxAuditBatch } = require('web-perf/crux');
const { runPsiAudit, runPsiAuditBatch }   = require('web-perf/psi');
const { runLabAudit }                      = require('web-perf/lab');

Available functions

Function	Module	Returns
`runLabAudit(url, options?)`	`web-perf/lab`	`Promise<LabReport>`
`runPsiAudit(url, apiKey, categories?)`	`web-perf/psi`	`Promise<PsiReport>`
`runPsiAuditBatch(urls, apiKey, categories, options?)`	`web-perf/psi`	`Promise<PsiBatchResult[]>`
`runCruxAudit(url, apiKey, options?)`	`web-perf/crux`	`Promise<CruxReport>`
`runCruxAuditBatch(urls, apiKey, options?)`	`web-perf/crux`	`Promise<CruxBatchResult[]>`
`runCruxHistoryAudit(url, apiKey, options?)`	`web-perf/crux-history`	`Promise<CruxHistoryReport>`
`runCruxHistoryAuditBatch(urls, apiKey, options?)`	`web-perf/crux-history`	`Promise<CruxHistoryBatchResult[]>`

// Single URL
const report = await runCruxAudit('https://example.com', apiKey, { scope: 'origin' });
console.log(report.metrics);

// Batch with progress
const results = await runCruxAuditBatch(urls, apiKey, {
  scope: 'page',
  concurrency: 5,
  onProgress: (done, total, url) => console.log(`${done}/${total}: ${url}`),
});

The CLI wrapper functions (runLab, runPsi, runCrux, runCruxHistory, …) are also exported and behave identically to the CLI commands — they write JSON to disk and return the output file path.

TypeScript

TypeScript type declarations are included and resolve automatically when you install the package. No @types/ package needed.

import { runCruxAudit, runPsiAudit } from 'web-perf';
import type { CruxReport, PsiReport, LabReport } from 'web-perf';

// Subpath imports also carry types
import { runCruxHistoryAudit } from 'web-perf/crux-history';
import type { CruxHistoryReport } from 'web-perf/crux-history';

Key exported types:

Type	Description
`LabReport`	Stripped Lighthouse JSON (categories, audits, formFactor, timing)
`PsiReport`	PageSpeed Insights API response (loadingExperience, lighthouseResult)
`CruxReport`	CrUX 28-day snapshot (metrics, collectionPeriod, scope, key)
`CruxHistoryReport`	CrUX historical snapshot (metrics, collectionPeriods array)
`CruxMetric`	Single CrUX metric (histogram bins, p75 percentile)
`PsiBatchResult`	`{ url, data: PsiReport \| null, error: string \| null }`
`CruxBatchResult`	`{ url, data: CruxReport \| null, error: string \| null }`
`CruxHistoryBatchResult`	`{ url, data: CruxHistoryReport \| null, error: string \| null }`

Development

# Clone and install dependencies
git clone https://github.com/your-org/web-perf-cli.git
cd web-perf-cli
npm install

# Run the CLI locally
node bin/web-perf.js lab https://example.com

Scripts

Script	Description
`npm test`	Run all tests (vitest)
`npm run lint`	Lint and auto-fix with ESLint
`npm run generate-types`	Regenerate `types/lib/*.d.ts` from JSDoc annotations

Regenerating types

Type declarations in types/lib/ are generated from JSDoc @typedef annotations in lib/. Run npm run generate-types after changing any return shape in a run*Audit function, then commit the updated types/ alongside the code change.

npm run generate-types
git add types/ lib/
git commit -m "feat: update CruxReport shape"

License

ISC

Name		Name	Last commit message	Last commit date
Latest commit History 69 Commits
.claude		.claude
.github		.github
.rtk		.rtk
.vscode		.vscode
bin		bin
docs		docs
lib		lib
types/lib		types/lib
.claudeignore		.claudeignore
.eslintrc		.eslintrc
.gitignore		.gitignore
CLAUDE.md		CLAUDE.md
README.md		README.md
commitlint.config.js		commitlint.config.js
package-lock.json		package-lock.json
package.json		package.json
tsconfig.types.json		tsconfig.types.json

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Repository files navigation

web-perf

Requirements

Quick Start

Google Cloud API key (for `psi`, `crux`, `crux-history`)

CLI Usage

Commands

`lab` — Local Lighthouse audit

Profiles

`psi` — PageSpeed Insights (real-user data)

Credential resolution order

`crux` — CrUX data (28-day rolling average)

`crux-history` — Historical CrUX data

`sitemap` — Sitemap URL extraction

`links` — Internal link extraction

Environment variables

Output structure

Library API

Available functions

TypeScript

Development

Scripts

Regenerating types

License

About

Uh oh!

Releases

Packages

Uh oh!

Uh oh!

Contributors

Uh oh!

Languages

Folders and files

Latest commit

History

Repository files navigation

web-perf

Requirements

Quick Start

Google Cloud API key (for psi, crux, crux-history)

CLI Usage

Commands

lab — Local Lighthouse audit

Profiles

psi — PageSpeed Insights (real-user data)

Credential resolution order

crux — CrUX data (28-day rolling average)

crux-history — Historical CrUX data

sitemap — Sitemap URL extraction

links — Internal link extraction

Environment variables

Output structure

Library API

Available functions

TypeScript

Development

Scripts

Regenerating types

License

About

Topics

Resources

Code of conduct

Contributing

Uh oh!

Stars

Watchers

Forks

Releases

Packages 0

Uh oh!

Uh oh!

Contributors

Uh oh!

Languages

Google Cloud API key (for `psi`, `crux`, `crux-history`)

`lab` — Local Lighthouse audit

`psi` — PageSpeed Insights (real-user data)

`crux` — CrUX data (28-day rolling average)

`crux-history` — Historical CrUX data

`sitemap` — Sitemap URL extraction

`links` — Internal link extraction

Packages