How Modern Browsers Process Security Headers
Modern web browsers implement sophisticated security mechanisms that interact with HTTP headers to provide layered protection. Understanding this interaction helps developers create more secure web applications.
Browser Security Architecture
1. Network Layer
Headers processed: HSTS, Expect-CT
2. Parser Layer
Headers processed: X-Content-Type-Options
3. Rendering Layer
Headers processed: X-Frame-Options, CSP
4. JavaScript Layer
Headers processed: CSP, Feature-Policy
Cross-Browser Header Support
| Header | Chrome | Firefox | Safari | Edge |
|---|---|---|---|---|
| Content-Security-Policy | Full | Full | Full | Full |
| Strict-Transport-Security | Full | Full | Full | Full |
| X-Frame-Options | Full | Full | Full | Full |
| Permissions-Policy | Partial | Partial | No | Partial |
Emerging Header Standards
Cross-Origin-Embedder-Policy (COEP)
Isolates document resources from cross-origin requests
Cross-Origin-Opener-Policy (COOP)
Prevents cross-origin window attacks like Spectre
Origin-Isolation
Provides process isolation for sensitive origins