HTTP Headers
NEL
HTTP Header
Experimental: This is an experimental technology
Please review the browser compatibility table carefully before implementing this in a production environment.
The HTTP NEL response header is utilized to configure network request logging for monitoring and debugging network performance.
Syntax
This configuration defines a reporting policy for network error logging. It specifies the report destination, maximum age, inclusion of subdomains, and the fractions of success and failure reports to be sent.
Note: Replace “name_of_reporting_group” with your actual reporting group name and customize other parameters as needed.
How to Modify Header using Requestly
Requestly is a powerful Chrome extension that allows you to modify HTTP headers, including the NEL header. This can help you simulate network error logging scenarios or control how browsers report network issues during development and testing. Steps to Modify the NEL Header:
- Install and open the Requestly Chrome extension. You can find it on the Chrome Web Store.
- Create a new rule: Click on “Create Rule” and choose “Modify Headers” from the list of available rule types.
- Add a new header modification:
- Under “Action”, select “Add” or “Override”.
- In the “Header Name” field, enter NEL.
- In the “Header Value” field, enter your desired NEL policy JSON as a string (e.g.,
{"report_to":"default","max_age":86400,"failure_fraction":0.1}).
- Set the URL condition: Specify the URL or pattern where this header change should apply (e.g., https://your-api.com/*).
- Save the rule.
Once set up, Requestly will inject the customized NEL header into all matching requests, allowing you to control how network error reporting behaves and test your server’s response to different error logging policies.
Modifying the NEL header is useful because it helps you test how your web application and backend handle network error logging policies, ensuring better monitoring and user experience in different network conditions.
Table of Contents
- No headings found.
