Security & Web Utilities • Published August 18, 2026

CORS vs CSP (Content Security Policy): Key Differences & When to Use Which

Understand the difference between Cross-Origin Resource Sharing (CORS) and Content Security Policy (CSP). Compare security models, directives, and use cases.

Demystify the differences between CORS and Content Security Policy (CSP). Understand their distinct security objectives, headers, and how they work together to protect web apps.

Frequently Asked Questions

Q1. Can Content Security Policy (CSP) fix my CORS error?

No. CSP directives like connect-src only specify which domains your frontend page is permitted to initiate connections to. Even if CSP allows connecting to an API, the API server must still return valid CORS headers for the browser to share the response with JavaScript.

Q2. Which header protects against Cross-Site Scripting (XSS)?

Content Security Policy (CSP). CSP prevents malicious injected scripts from executing and blocks unauthorized data exfiltration.