Merlin
Modify Header Value

Modify Header Value

Add, modify or remove a header for any request on desired domains.

What is Modify Header Value?
"Modify Header Value" is a Firefox extension designed for app developers, website designers, and testers who wish to modify HTTP-request-headers. This extension enables users to easily add, change, or remove an HTTP-request-header for every request on the desired domains or URLs. One can deactivate or activate the add-on or individual header items with a simple toolbar icon click. The extension comes with an options page for the adjustment of each header item and an illustrative example on adding custom headers.
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Merlin
Stats
By: Milen
Rating: 3.95 (55)
Version: 0.1.8 (Last updated: 2022-08-01)
Creation date: 2015-07-06
Weekly download count: 213
Firefox on Android: Yes
Risk impact: High risk impact
Risk likelihood: Low risk likelihood
Manifest version: 2
Permissions:
  • storage
  • <all_urls>
  • webRequest
  • webRequestBlocking
Size: 105.42K
URLs: Website
Stats date:

Chrome-Stats Rank

# 808 ▼ 3
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Other platforms

Modify Header Value (HTTP Headers)
Modify Header Value (HTTP Headers) (v0.1.9)
3.38 (42) 40,000
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Merlin
Summary
Analyze keywords

Modify Header Value can add, modify or remove an HTTP-request-header for all requests on a desired website or URL. This Firefox add-on is very useful if you are an App developer, website designer, or if you want to test a particular header for a request on a website.

Key features:

  1. Easily add, modify or remove a header for any request on a desired domain(s).
  2. For a complete list of HTTP headers, please take a look at the list of HTTP Header Fields in Wikipedia.
  3. Clicking on the Toolbar icon allows you to disable or enable the addon.
  4. Each header item has several options to adjust (see add-on's Options page for details)
  5. You can add several header items and active or inactive them separately.
  6. An example in the options page shows a tutorial on "How to add a custom header".

Note: to report bugs, please visit add-on's homepage and fill the bug report form.

Review on YouTube: https://www.youtube.com/watch?v=KM4uKx-BjIg

User reviews
User reviews summary
These summaries are automatically generated weekly using AI based on recent user reviews. Firefox Browser Add-ons does not verify user reviews, so some user reviews may be inaccurate, spammy, or outdated.
Pros
  • Allows users to tweak any header they desire
  • Works in private mode
  • Works properly/at all for spoofing a referer
Cons
  • Unable to work around CORs protection to test code in console
  • UI needs refinement
  • Headers value cannot be changed once configured
  • User-unfriendliness of modifying rules
Most mentioned
  • UI needs refinement
  • Headers value cannot be changed once configured
  • User-unfriendliness of modifying rules
Recent reviews
by Firefox user 14427289, 2023-07-04
View all user reviews
Safety
Risk impact

Modify Header Value is risky to use as it requires a number of sensitive permissions that can potentially harm your browser and steal your data. Exercise caution when installing this add-on. Review carefully before installing. We recommend that you only install Modify Header Value if you trust the publisher.

Risk likelihood

Modify Header Value has earned a fairly good reputation and likely can be trusted.

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Screenshots
Modify Header Value Modify Header Value Modify Header Value