Telescope

Telescope

A cross-browser web performance testing toolkit built on [Playwright](https://playwright.dev/). This repository is a monorepo containing two packages:

Package	Description
`packages/telescope`	Core CLI and library (@cloudflare/telescope)
`packages/telescope-web`	Web app for uploading and viewing results (telescopetest.io)

---

packages/telescope

A TypeScript CLI and Node.js library that launches real browsers, collects performance data, and saves results locally.

**Supported browsers:** Chrome, Chrome Beta, Chrome Canary, Edge, Firefox, Safari (WebKit)

**What it collects per test:**

• HAR file (pageload.har)
• Web Vitals and performance metrics (metrics.json)
• Console output (console.json)
• Resource timing data (resources.json)
• Screenshot (screenshot.png)
• Filmstrip and video of the page load

Quick start

Install from npm:

npm install -g @cloudflare/telescope
telescope -u https://example.com -b chrome

The `postinstall` script automatically downloads Playwright's browser binaries (~700MB).

Or from a clone of this repo:

npm install
npm run build -w packages/telescope
npm link                          # registers `telescope` globally
telescope -u https://example.com -b chrome

See [`packages/telescope/README.md`](./packages/telescope/README.md) for full documentation.

---

packages/telescope-web

The Astro + Cloudflare Workers web application hosted at [telescopetest.io](https://telescopetest.io). Users upload Telescope ZIP results and view an interactive breakdown of metrics, waterfal