Cross-Browser Extension Compatibility

Comprehensive guide to writing browser extensions that work across Chrome, Firefox, Safari, and Edge with proper feature detection and polyfills.

Overview

Browser extensions share a common WebExtensions API standard, but implementations differ significantly. This skill covers how to handle those differences.

This skill covers:

• API compatibility matrices
• Polyfill usage and patterns
• Feature detection techniques
• Browser-specific workarounds
• Manifest differences

This skill does NOT cover: