What is Content Security Policy?

Content Security Policy is an HTTP response header that tells the browser which sources a page may load scripts, styles, frames and other resources from. It is a defence-in-depth measure against cross-site scripting.

Primary sources

Specifications cited by the tools below whose own titles define Content Security Policy.

Content Security Policy Level 3W3C

3 tools that work with Content Security Policy

Files never leave your browser.

Developer Tools2

Content Security Policy GeneratorBuild a CSP header from common presets, with each directive explained.HTTP Security Header AnalyserPaste response headers and get a security grade, with what is missing and why it matters.

Network Tools1

HTTP Header CheckerFollow every redirect, grade the security headers and read the cookie and caching settings.

Related terms

Terms that appear alongside Content Security Policy on the same tools.

HTTP Strict Transport Security
Cross-site scripting
HTTP header
OWASP
URL redirection

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