1. In a browser page, right-click anywhere and select Inspect Element.

2. The developer tools either appear at the bottom or left side of the browser. Click the Network tab. 

3. Check Preserve log.

4. Click record.

5. Browse to the URL that causes issues. Once the issue is experienced, right click on any of the items within the Network tab and select Save all as HAR with Content.

 6. Attach the HAR file to your support ticket.

1. From the application menu, select Tools > Web Developer > Network or press Ctrl+Shift+I (Windows/Linux) or Cmd+Option+I (OS X).

2. Browse to the URL that causes issues.

3. After duplicating the issue, right-click and choose Save All As HAR.

2. Browse to the URL that causes issues.

3. After duplicating the issue, click on Export as HAR followed by Save As....

1. In Safari, ensure a Develop menu appears at the top of the browser window. Otherwise, go to Safari > Preferences > Advanced and select Show Develop Menu in menu bar

2. Navigate to Develop > Show Web Inspector.

3. Browse to the URL that causes issues.

4. Ctrl + click on a resource within Web Inspector and click Export HAR.

When troubleshooting HTTP errors in responses from Cloudflare, test whether your origin caused the errors by sending requests directly to your origin web server. To troubleshoot HTTP errors, run a cURL directly to your origin web server IP address (bypassing Cloudflare’s proxy):

curl -svo /dev/null http://example.com --connect-to ::203.0.113.34

cURL measures latency or performance degradation for HTTP/HTTPS requests via the -w or --write-out cURL options. The example cURL below measures several performance vectors in the request transaction such as duration of the TLS handshake, DNS lookup, redirects, transfers, etc:

curl -svo /dev/null https://example.com/ -w "\nContent Type: %{content_type} \
\nHTTP Code: %{http_code} \
\nHTTP Connect:%{http_connect} \
\nNumber Connects: %{num_connects} \
\nNumber Redirects: %{num_redirects} \
\nRedirect URL: %{redirect_url} \
\nSize Download: %{size_download} \
\nSize Upload: %{size_upload} \
\nSSL Verify: %{ssl_verify_result} \
\nTime Handshake: %{time_appconnect} \
\nTime Connect: %{time_connect} \
\nName Lookup Time: %{time_namelookup} \
\nTime Pretransfer: %{time_pretransfer} \
\nTime Redirect: %{time_redirect} \
\nTime Start Transfer: %{time_starttransfer} \
\nTime Total: %{time_total} \
\nEffective URL: %{url_effective}\n" 2>&1

Explanation of this timing output is found on the Cloudflare blog.

cURL helps review the HTTP response headers that influence caching. In particular, review several HTTP headers when troubleshooting Cloudflare caching:

• CF-Cache-Status
• Cache-control/Pragma
• Expires
• Last-Modified
• S-Maxage

Reviewing Certificates with cURL

The following cURL command shows the SSL certificate served by Cloudflare during an HTTPS request (replace www.example.com with your domain and host name):

curl -svo /dev/null https://www.example.com/ 2>&1 | egrep -v "^{.*$|^}.*$|^\* http.*$"

To display the origin certificate (assuming one is installed), replace 203.0.113.34 below with the actual IP address of your origin web server and replace www.example.com with your domain and host name:

curl -svo /dev/null https://www.example.com --connect-to ::203.0.113.34 2>&1 | egrep -v "^{.*$|^}.*$|^\* http.*$"

Testing TLS Versions

If troubleshooting browser support or confirming what TLS versions are supported, cURL allows you to test a specific TLS version by adding one of the following options to your cURL:

• --tlsv1.0
• --tlsv1.1
• --tlsv1.2
• --tlsv1.3

1. Open the Start menu.

2. Click Run.

3. To open the command line interface, type cmd and then click OK.

4. At the command line prompt, type: For IPv4 -

> tracert www.example.com

For IPv6 -

> tracert -6 www.example.com

5. Press Enter.

6. You can copy the results to save in a file or paste in another program.

1. Open a terminal window.

2. At the command line prompt, type:

For IPv4 -

> traceroute www.example.com

For IPv6 -

> traceroute -6 www.example.com

3. You can copy the results to save in a file or paste in another program.

1. Open the Network Utility application.
2. Click the Traceroute tab.
3. Type the domain or IP address in the appropriate input field and press Trace.
4. You can copy the results to save in a file or paste in another program.

Alternatively, follow the same Linux traceroute instructions above when using the Mac OS terminal program.

LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-agent}i\" %{CF-Ray}i" cf_custom

log_format cf_custom '$remote_addr - $remote_user [$time_local] '
'"$request" $status $body_bytes_sent '
'"$http_referer" "$http_user_agent" '
'$http_cf_ray';