BrowserLoop▌

by mattiasw
BrowserLoop: Capture web screenshots on Chrome with advanced screenshot taker add-on for web testing, visual verificatio
Captures web page screenshots using Playwright with support for full-page, element-specific, and viewport screenshots in PNG, JPEG, and WebP formats, featuring cookie authentication, domain filtering, and configurable quality settings for web testing and visual verification workflows.
best for
- / Web developers testing visual changes
- / QA engineers doing visual verification
- / Debugging browser console errors
- / Automated screenshot workflows
capabilities
- / Take full-page screenshots
- / Capture specific element screenshots
- / Monitor browser console logs
- / Export in PNG, JPEG, and WebP formats
- / Authenticate with cookies
- / Configure image quality settings
what it does
Captures web page screenshots using Playwright with support for different formats, element targeting, and authentication. Also monitors browser console logs for debugging and testing workflows.
about
BrowserLoop is a community-built MCP server published by mattiasw that provides AI assistants with tools and capabilities via the Model Context Protocol. BrowserLoop: Capture web screenshots on Chrome with advanced screenshot taker add-on for web testing, visual verificatio It is categorized under browser automation.
how to install
You can install BrowserLoop in your AI client of choice. Use the install panel on this page to get one-click setup for Cursor, Claude Desktop, VS Code, and other MCP-compatible clients. This server runs locally on your machine via the stdio transport.
license
AGPL-3.0
BrowserLoop is released under the AGPL-3.0 license.
readme
BrowserLoop
⚠️ ARCHIVED: This project is archived and will not receive any further updates. With the release of Chrome DevTools MCP, a dedicated MCP server for browser automation is no longer necessary as that project provides more comprehensive browser interaction capabilities including screenshots, console monitoring, and much more.
A Model Context Protocol (MCP) server for taking screenshots and reading console logs from web pages using Playwright. This tool allows AI agents to automatically capture screenshots and monitor browser console output for debugging, testing, and development tasks.
NOTE: Almost all of the code in this repository has been auto-generated. That means you should probably not trust it too much. That being said, it does work and I'm using it myself.
NOTE: If the documentation is incorrect, please let me know or send a PR. If you too want to use a code generation tool to update the code for this project, PROJECT_CONTEXT.md has been used as context to give a good overview of the various parts of the project. It might be a bit messy now but it's a good starting point and you're welcome to update it.
Features
- 📸 High-quality screenshot capture using Playwright
- 📝 Console log monitoring and collection from web pages
- 🌐 Support for localhost and remote URLs
- 🍪 Cookie-based authentication for protected pages
- 🐳 Docker containerization for consistent environments
- ⚡ PNG, JPEG, and WebP format support with configurable quality
- 🛡️ Secure non-root container execution
- 🤖 Full MCP protocol integration with AI development tools
- 🔧 Configurable viewport sizes and capture options
- 📱 Full page and element-specific screenshot capture
- ⚠️ Browser warning and error capture (Permissions-Policy, security warnings)
- ⚡ TypeScript with Biome for fast development
- 🧪 Comprehensive testing with Node.js built-in test runner
Quick Start
📦 NPX Usage (Recommended)
The easiest way to get started - no installation required!
# Install Chromium browser (one-time setup)
npx playwright install chromium
# Test that BrowserLoop works
npx browserloop@latest --version
That's it! The latest version of BrowserLoop will be downloaded and executed automatically. Perfect for MCP users who want zero-maintenance screenshots.
MCP Configuration
Add BrowserLoop to your MCP configuration file (e.g. ~/.cursor/mcp.json):
{
"mcpServers": {
"browserloop": {
"command": "npx",
"args": ["-y", "browserloop@latest"],
"description": "Screenshot and console log capture server for web pages using Playwright"
}
}
}
💡 Using @latest ensures you always get the newest features and bug fixes automatically.
🚀 One-Click Install for Cursor
Add BrowserLoop to Cursor with a single click using this deeplink:
This deeplink will automatically configure BrowserLoop in your Cursor MCP settings with the optimal configuration using npx and the latest version.
Prerequisites: Make sure you have Chromium installed first:
npx playwright install chromium
Browser Installation Requirements
🚨 Critical: BrowserLoop requires Chromium to be installed via Playwright before it can take screenshots.
First-Time Setup (All Users)
Install Chromium browser:
npx playwright install chromium
Verify installation:
# Check Playwright installation
npx playwright --version
# Test BrowserLoop (if using NPX)
npx browserloop@latest --version
🐳 Docker Alternative
For containerized environments:
# Pull and run with Docker
docker run --rm --network host browserloop
# Or use docker-compose for development
git clone <repository-url>
cd browserloop
docker-compose -f docker/docker-compose.yml up
💻 Development Installation
For contributors or advanced users who want to build from source:
# Clone the repository
git clone <repository-url>
cd browserloop
# Install dependencies
npm install
# Install Playwright browsers (required for screenshots)
npx playwright install chromium
# OR use the convenient script:
npm run install-browsers
# Build the project
npm run build
MCP Configuration for Development
{
"mcpServers": {
"browserloop": {
"command": "node",
"args": [
"/absolute/path/to/browserloop/dist/src/index.js"
],
"description": "Screenshot and console log capture server for web pages using Playwright"
}
}
}
Replace /absolute/path/to/browserloop/ with your actual project path.
Basic Usage
Once configured, you can use natural language commands in your AI tool:
Screenshots
Take a screenshot of https://example.com
Take a screenshot of https://example.com with width 1920 and height 1080
Take a screenshot of https://example.com in JPEG format with 95% quality
Take a full page screenshot of https://example.com
Take a screenshot of http://localhost:3000 to verify the UI changes
Console Log Reading
Read console logs from https://example.com
Check for console errors on https://example.com
Monitor console warnings from http://localhost:3000
Read only error and warning logs from https://example.com
Capture console output from https://example.com for debugging
🔐 Cookie Authentication
BrowserLoop supports cookie-based authentication for capturing screenshots of login-protected pages during development:
Take a screenshot of http://localhost:3000/admin/dashboard using these cookies: [{"name":"connect.sid","value":"s:session-id.signature","domain":"localhost"}]
📖 For cookie extraction methods and development workflows, see:
Common development use cases:
- Local development servers with authentication
- Staging environment testing
- API documentation tools (Swagger, GraphQL Playground)
- Custom web applications during development
- Admin panels and protected routes
Documentation
- 🔐 Cookie Authentication Guide - Complete guide for authenticated screenshots
- 📚 Complete API Reference - Detailed parameter documentation, examples, and response formats
Key API Parameters
| Parameter | Type | Description | Default |
|---|---|---|---|
url | string | Target URL to capture (required) | - |
width | number | Viewport width (200-4000) | 1280 |
height | number | Viewport height (200-4000) | 720 |
format | string | Image format (webp, png, jpeg) | webp |
quality | number | Image quality (1-100) | 80 |
fullPage | boolean | Capture full page | false |
selector | string | CSS selector for element capture | - |
📖 See docs/API.md for complete parameter details, usage examples, and configuration options.
Configuration
BrowserLoop can be configured using environment variables:
Basic Configuration
| Variable | Default | Description |
|---|---|---|
BROWSERLOOP_DEFAULT_WIDTH | 1280 | Default viewport width (200-4000) |
BROWSERLOOP_DEFAULT_HEIGHT | 720 | Default viewport height (200-4000) |
BROWSERLOOP_DEFAULT_FORMAT | webp | Default image format (webp, png, jpeg) |
BROWSERLOOP_DEFAULT_QUALITY | 80 | Default image quality (0-100) |
BROWSERLOOP_DEFAULT_TIMEOUT | 30000 | Default timeout in milliseconds |
BROWSERLOOP_USER_AGENT | - | Custom user agent string |
Authentication Configuration
| Variable | Default | Description |
|---|---|---|
BROWSERLOOP_DEFAULT_COOKIES | - | Default cookies as file path or JSON string (see Cookie Authentication Guide) |
Console Log Configuration
| Variable | Default | Description |
|---|---|---|
BROWSERLOOP_CONSOLE_LOG_LEVELS | log,info,warn,error,debug | Comma-separated list of log levels to capture |
BROWSERLOOP_CONSOLE_TIMEOUT | 30000 | Page navigation timeout in milliseconds (not log collection time) |
BROWSERLOOP_SANITIZE_LOGS | true | Enable/disable sensitive data sanitization in logs |
BROWSERLOOP_CONSOLE_WAIT_NETWORK_IDLE | true | Wait for network idle before finishing collection |
BROWSERLOOP_MAX_LOG_SIZE | 1048576 | Maximum total log size in bytes (1MB) |
Note: Console log collection always waits exactly 3 seconds after page load to capture console messages. The timeout setting only affects how long the page has to initially load.
Log Sanitization
Console log sanitization is enabled by default (BROWSERLOOP_SANITIZE_LOGS=true) to protect sensitive information. When enabled, the following patterns are automatically masked:
| Pattern Type | Example Input | Masked Output |
|---|---|---|
| API Keys | sk_live_1234567890abcdef... | [API_KEY_MASKED] |
| Email Addresses | user@example.com | [EMAIL_MASKED] |
| JWT Tokens | eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9... | [JWT_TOKEN_MASKED] |
| Auth Headers | Bearer abc123token... | [AUTH_HEADER_MASKED] |
| URLs with Auth | https://api.com/data?token=secret123 | [URL_WITH_AUTH_MASKED] |
| **Secret Variabl |