CentralCSP Chrome Extension
CentralCSP Chrome Extension: Test Your CSP Without Server Changes
Testing Content Security Policy (CSP) implementations can be challenging, especially when you need to modify server configurations for each test. The CentralCSP Chrome Extension solves this problem by allowing you to test CSP policies directly in your browser without touching your server. Whether you're a developer debugging CSP violations, a security professional validating policies, or a DevOps engineer testing different configurations, this extension provides the flexibility you need to iterate quickly and safely.What is the CentralCSP Chrome Extension?
The CentralCSP Chrome Extension is a powerful browser tool that allows you to override and test Content Security Policy headers on any webpage without modifying server configurations. It's designed for development, testing, and debugging purposes, giving you complete control over CSP testing in your browser.Key capabilities:
- Override existing CSP headers on any website
- Test both enforce and report-only modes instantly
- No server changes required - test on live sites safely
- Local testing environment for policy validation
- Instant policy switching for rapid iteration
Why Use a Chrome Extension for CSP Testing?
Traditional CSP testing requires server-side changes, which can be time-consuming and risky. Here's why the Chrome extension approach is superior:1. No Server Access Required
Test CSP policies on any website, including production sites, without needing server access or deployment permissions.2. Instant Iteration
Switch between different policies instantly without waiting for server restarts or deployments.3. Safe Testing Environment
Test potentially breaking policies without affecting other users or production systems.4. Real Browser Behavior
See exactly how your CSP will behave in a real browser environment with actual resource loading.How to Install the Extension
Installing the CentralCSP Chrome Extension is straightforward:Step 1: Visit the Chrome Web Store
Navigate to the CentralCSP Chrome Extension page in your Chrome browser.Step 2: Add to Chrome
Click the "Add to Chrome" button and confirm the installation when prompted.Step 3: Pin the Extension (Recommended)
Right-click the extension icon in your browser toolbar and select "Pin" to keep it easily accessible.
How to Use the Extension
Once installed, using the extension is simple and intuitive:Step 1: Navigate to Your Target Website
Open the website where you want to test your CSP policy in a new tab.Step 2: Open the Extension
Click the CentralCSP extension icon in your browser toolbar to open the popup interface.Step 3: Configure Your Policy
- Toggle the extension ON using the switch at the top
- Enter your CSP policy in the text area
- Choose your mode: Enforced or Report-Only
- Refresh the page to apply the new policy
Step 4: Test and Iterate
- Monitor browser console for CSP violations
- Check network requests to see which resources are blocked
- Modify your policy as needed and refresh to test changes
- Switch between modes to compare behavior
Understanding the Interface
The extension interface is designed for simplicity and efficiency:Main Controls
Toggle Switch: Enable or disable the extension- ON: Extension will override CSP headers
- OFF: Extension is inactive, original headers remain
- Enforced: Policy actively blocks violating resources
- Report-Only: Policy reports violations but doesn't block resources
Example Policy Input
Example CSP policy for testing in the extension
default-src 'self';
script-src 'self' 'report-sample';
style-src 'self';
img-src 'self';
font-src 'self';
object-src 'none';
base-uri 'none';
form-action 'none';
frame-ancestors 'none';
frame-src 'self';
connect-src 'none';
upgrade-insecure-requests;
report-uri https://report.centralcsp.com/<myendpoint>;Testing Scenarios
The extension is perfect for various testing scenarios:1. Policy Development
Test new CSP policies before deploying to production:- Start with a report-only mode to identify violations
- Gradually tighten the policy based on violation data
- Switch to enforced mode to test the final policy
- Iterate quickly without server changes
2. Debugging Existing Policies
Troubleshoot CSP violations on live sites:- Override the existing policy with a more permissive one
- Identify which resources are being blocked
- Gradually tighten the policy to find the optimal configuration
- Test the final policy before implementing server-side
3. Client-Side CSP Validation
Validate policies for client-side applications:- Test how your policy affects JavaScript frameworks
- Verify that third-party integrations work correctly
- Ensure inline scripts and styles are handled properly
Best Practices for Extension Usage
To get the most out of the CentralCSP Chrome Extension, follow these best practices:1. Start with Report-Only Mode
Always begin testing in report-only mode to understand what your policy will block without breaking functionality.2. Test on Multiple Pages
Don't just test on the homepage - test on various pages throughout your site to ensure comprehensive coverage.3. Monitor Browser Console
Keep the browser console open to see CSP violation reports and understand what's being blocked.4. Test Different Browsers
While the extension is Chrome-specific, test your final policy in other browsers to ensure compatibility.5. Document Your Findings
Keep notes on which policies work best for different scenarios to inform your production implementation.Troubleshooting Common Issues
Extension Not Working
- Check if the toggle is ON - The extension must be enabled
- Refresh the page after making changes
- Clear browser cache if policies seem cached
- Check browser console for any error messages
Policy Not Applied
- Verify syntax - Check for typos in your CSP directives
- Ensure proper formatting - Each directive should end with a semicolon
- Check mode selection - Make sure you've selected the correct mode
Resources Still Loading When Blocked
- Verify you're in Enforced mode - Report-Only mode won't block resources
- Check directive syntax - Ensure your policy is correctly formatted
- Test with a stricter policy - Try
default-src 'none'to verify blocking works
Security Considerations
Development Use Only
The CentralCSP Chrome Extension is designed for development and testing purposes only. Never use it to disable security policies in production environments.Local Testing
The extension only affects your local browser session. Other users and production systems remain unaffected.Policy Validation
Always validate your final policy using proper CSP testing tools before implementing in production.Integration with CentralCSP Platform
The Chrome Extension works seamlessly with the CentralCSP platform:- Generate policies using the CSP Builder
- Test policies with the Chrome Extension
- Monitor violations using CentralCSP reporting
- Deploy validated policies to production
Get Started Today
Ready to streamline your CSP testing process? The CentralCSP Chrome Extension is free and available now:Install the CentralCSP Chrome Extension and start testing your Content Security Policy without server changes.
Need Help?
If you encounter any issues or have questions about using the extension:- Check the FAQ section on our extension page
- Review browser console for error messages
- Test with simple policies first to verify functionality
- Contact our support team for additional assistance
Continue Reading
How to use the Content-Security-Policy (CSP) Builder
Learn how to use the Content-Security-Policy (CSP) Builder to generate a policy based on actual usage patterns.
2025-07-26
5 min read
Theotime QuereRead more
Understand Bitsight new Web Application Security (WAS) algorithm
Learn how to understand Bitsight new Web Application Security (WAS) algorithm. See how to avoid CSP violations & misconfiguration findings. Fix issues & prevent score drops.
2025-07-15
5 min read
Theotime QuereRead more
