You’re deploying a new feature and need to lock down your site against cross-site scripting, but the Content Security Policy spec reads like ciphertext. A stray semicolon or a missing quote can silently break legitimate resources or leave a gaping hole an attacker will find in minutes. CSP Builder turns that friction into a fast visual configuration—no memorizing directive syntax, no guesswork, just a clean policy string ready for production.
What it is
CSP Builder is a visual Content Security Policy generator, part of the DevTools collection of 200+ free browser utilities. Content Security Policy (CSP) is a critical web security standard that prevents XSS and code injection by telling the browser exactly which content sources to trust. Instead of writing raw policy strings, you compose directives through a form-based interface that enforces the correct syntax and catches common missteps as you go.
The tool treats each CSP directive—default-src, script-src, style-src, img-src, and more—as an independent row. For every directive, you pick sources from a curated list or type custom URLs. The output is a syntactically valid Content-Security-Policy header that you can drop into your web server configuration or application middleware without further massaging.
