What Is the Difference Between DevTools and Browser Extensions

Short answer

DevTools is a built-in suite for debugging and profiling web pages. Browser extensions add external functionality but cannot directly access all internal browser APIs that DevTools uses.

Key differences

• Scope: DevTools inspects any page; extensions run only on allowed domains.
• API access: DevTools uses the Chrome DevTools Protocol; extensions use the WebExtensions API.
• Performance: DevTools profiling is more detailed than what extensions can capture.
• Persistence: Extensions remain active across sessions; DevTools closes with the tab.

When to use each

• Use DevTools for deep debugging, performance profiling, and network analysis.
• Use extensions for quick checks, design overlays, cookie management, and daily workflow enhancements.