1001Ferramentas
Tools Categories Guides FAQ
About Contact Privacy Policy Terms of Use
📡Dev

HAR Viewer

Read pasted HAR (HTTP Archive) and list requests with method, status, URL and time.


  


  






    
    
    

      

        
        

          
Reading a HAR without opening a browser

          
          
          

            
HAR is the format a browser exports the network tab in: JSON with one entry per request, each carrying timings, headers and sizes. Paste the file and the page summarises what matters first — how many requests, how much was transferred, how many errors, which was slowest — then lists the requests.

            
The summary exists because the question that makes someone open a HAR is almost never about one specific request. It is about the whole: why the page is heavy, what is failing, what is not being cached. The count of 304 responses helps with that last one — they show revalidation happening, which saves bandwidth but still costs a round trip.

            
An important warning about the content: a HAR holds headers and, depending on how it was exported, response bodies. That means session cookies, authorisation tokens and personal data inside a text file. Before attaching a HAR to a support ticket it needs sanitising — browsers offer an option to export without sensitive content, and it is worth using.

          

        

        
        
        
        

          
Frequently asked questions

          

            
            

              How do you generate a HAR?
              
In the network tab of the developer tools, with recording on, reload the page and use the export option. It is important to tick the option to preserve the log before reloading, otherwise navigation clears what was captured up to that point.

            

            
            

              Why do some sizes show as unknown?
              
Because the format uses minus one to say the value is unavailable, which happens for responses served from cache and in some compression scenarios. The page handles that case rather than adding the negative value, which is what produces a negative transfer total in careless tools.

            

            
            

              Is the total time the sum of the times?
              
No, and that is the commonest misreading. Requests happen in parallel, so adding the times gives a number far larger than the real load time. What matters is the page load event time and which requests sit on the critical path.

            

            
          

        

        
      

    

    
    
    
    
    

      



  
Related Tools

  

    
      
  

    💾
    

      
Cache-Control Parser

      
Read a Cache-Control header and show each directive (max-age, no-cache, public, immutable, stale-while-revalidate) with explanation.

    

  



    
      
  

    🤝
    

      
HTTP Accept Header Content Negotiation Matcher

      
Paste a client Accept header and the comma-separated media types a server offers to see which one wins and at what q value. Exact types and */* only.

    

  



    
      
  

    🍪
    

      
HTTP Cookie Parser

      
Paste a Set-Cookie header and inspect name, value, Domain, Path, Expires, Max-Age, HttpOnly, Secure and SameSite separately. Browser-only.

    

  



    
      
  

    🔤
    

      
Accept-Charset Header Parser

      
Breaks an Accept-Charset header into charsets and q-values and ranks them by preference. The header is deprecated; today's clients simply assume UTF-8.

    

  



    
      
  

    📊
    

      
CSV Validator & Viewer

      
Validate, parse and visualize CSV data in table format. Automatically detects delimiters (comma, semicolon or tab) and highlights formatting errors.

    

  



    
      
  

    🌐
    

      
HTTP Request Builder

      
Build an HTTP request (URL, method, headers, body) and generate snippets in cURL, fetch, axios, Python requests and Go net/http. Everything in your browser.