HTTP Headers Checker

Analyze pasted HTTP response headers for cache, redirects, security headers and content-type issues without making server-side requests.

This tool does not fetch remote URLs. Paste headers from curl or browser DevTools, then use the generated command for repeatable checks.
Header analysis 

        

    

                

            
                    

                        
How to use this tool

                        
    
                                                            
  1. Run curl -I https://example.com or copy response headers from browser DevTools.
    2. 
                                                            
  2. Paste the status line and headers into the textarea.
    3. 
                                                            
  3. Review security, cache, redirect and content-type warnings.
    4. 
                                                            
  4. Use the generated curl command as a repeatable verification step.
    5. 
                                                    

                    


                    

                        
Common mistakes

                        
    
                                                            
  • Checking only the homepage and missing headers on assets, APIs or redirected URLs.
    • 
                                                            
  • Adding HSTS before HTTPS is stable on every required subdomain.
    • 
                                                            
  • Using conflicting cache-control headers between the origin, CDN and application.
    • 
                                                    

                    


                    

                        
FAQ

                        

                                                            

                                    Does this tool fetch my URL?
                                    
No. It analyzes headers you paste locally in the browser and provides curl commands for your own terminal.

                                

                                                            

                                    Which security headers does it check?
                                    
It checks common signals such as Strict-Transport-Security, Content-Security-Policy, X-Frame-Options, X-Content-Type-Options and Referrer-Policy.

                                

                                                            

                                    Can it prove a site is secure?
                                    
No. Header checks are only one part of a web security review.

                                

                                                    

                    


                        

        
Related tools

        

                                                
                        Nginx
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                        Apache
                        .htaccess Redirect Generator
                        
Create Apache .htaccess redirect rules for URL migrations, canonical host changes, and HTTP to HTTPS cleanup.

                    
                                                                
                        SSL
                        SSL Checker Command Helper
                        
Generate safe terminal commands for checking SSL certificates, HTTPS redirects, issuer, SAN names and expiry without storing credentials.

                    
                                    

    

                            

        
Related guides and fixes

        

                                                
                        cURL
                        cURL API Debugging Workflow for Developers
                        
cURL is the simplest way to separate API behavior from SDK, framework or frontend code. Build a minimal request first, then compare it with the failing implementation.

                    
                                                                
                        HTTP
                        Debug HTTP 429 Rate Limit Errors
                        
A 429 response means the request was understood but rate limited. The fastest fix is to inspect headers, reduce concurrency and prove the behavior with a minimal request.

                    
                                                                            
                        HTTP
                        HTTP 403 vs 401 Fix
                        
401 and 403 are both access failures, but they point to different checks. Debug the auth header, user permissions and proxy rules separately.

                    
                                                                
                        JS
                        JavaScript Failed to Fetch Fix
                        
Failed to fetch is a browser-level failure. You need to inspect the Network tab and server headers before changing application state code.

                    
                                    

    

                        
Last updated: May 17, 2026