CORS dev tool Firefox

CORS dev tool

By: Atom
Lightweight CORS web development tool allows developers to modify Ajax responses Access-Control-Allow-Origin: * and other configurations

Features & Capabilities

Users can set different return values to allow users to be granted access to specified resources from different source servers. Users can customize the value of the HTTP response header -Access-Control-Allow-Origin specifies either a single origin, which tells browsers to allow that origin to access the resource; -Access-Control-Expose-Headers header lets a server whitelist headers that browsers are allowed to access. -Access-Control-Max-Age header indicates how long the results of a preflight request can be cached. -Access-Control-Allow-Credentials header Indicates whether or not the response to the request can be exposed when the credentials flag is true. -Access-Control-Allow-Methods header specifies the method or methods allowed when accessing the resource. This is used in response to a preflight request.

  • Access-Control-Allow-Headers header is used in response to a preflight request to indicate which HTTP headers can be used when making the actual request.

It should be noted that when Access-Control-Allow-Origin is set to "*", the identity certificate cannot be attached. Of course you can specify a unique Origin such as http://localhost:3000

Instructions After installing the plugin, click the icon in the upper right corner to enable "cross-source resource sharing".

Custom configuration After installing the plugin, click the icon in the upper right corner and click "Customize" to enter the configuration page.

The "HTTP Response Header" page allows you to add custom Access-Control-* header information to the HTTP response header "Url Mode" page allows you to customize the website for applying rules

Compatible browser Firefox v48+

User Growth & Download Statistics

Manifest V2 Add-on
By:
Atom
Daily users:
15 1
Rating:
5.00
(2)
Version:
1.1.4 Last updated: 2020-08-24
Version code:
5086197
Creation date:
2019-05-24
Risk:
Low risk impact Low risk likelihood
Permissions:
  • *://janbao.net/*
  • *://jandan.net/*
  • *://*.jandan.net/*
Content scripts matches:
  • janbao.net
  • jandan.net
  • *.jandan.net
Size:
65.52KB
Email:
jh*****@gmail.com
URLs:
Website
Full description:
See detailed description
Source:
Firefox Add-ons Store
Data ingested on:
2026-06-18
Compare stats and ranking:

Other platforms

Chrome
CORS Helper (v1.2.2)
1,000 3.67 (3)

Contact the developer

Chrome-Stats does not own this Firefox add-on. Please use these information below to contact the Firefox add-on developer.
Developed by:
Atom
Firefox Add-ons Store
https://addons.mozilla.org/firefox/addon/cors-dev-tool/
Email:
jh*****@gmail.com
Website:
https://github.com/jhrxx/CORS-dev-tool

User Reviews

by 退出*****, 2025-04-10

by 天灭*****, 2025-03-18

by Fi*****, 2020-02-20
View all user reviews ›

Is CORS dev tool Safe?

Risk impact
Risk impact measures the level of extra permissions an extension has access to. A low risk impact extension cannot do much harms, whereas a high risk impact extension can do a lot of damage like stealing your password, bypassing your security settings, and accessing your personal data. High risk impact extensions are not necessarily malicious. However, if they do turn malicious, they can be very harmful.

CORS dev tool requires very minimum permissions.

Risk impact analysis details
  • High Injects scripts into web pages, which may alter or extract site contents, resulting in a substantial risk.
  • Low ******* ****** ** *** ********* ******** *********** **********
Risk likelihood
Risk likelihood measures the probability that a Firefox add-on may turn malicious. This is determined by the publisher and the Firefox add-on reputation on Firefox Add-ons Store, the amount of time the Firefox add-on has been around, and other signals about the Firefox add-on. Our algorithms are not perfect, and are subject to change as we discover new ways to detect malicious extensions. We recommend that you always exercise caution when installing a Firefox add-on.

CORS dev tool has earned a fairly good reputation and likely can be trusted.

Risk likelihood analysis details
  • High This extension has low user count. Unpopular extensions may not be stable or safe.
  • Low **** ********* *** ******* **** **** * ****** **** ***** ******** *** **** ****** ** ** ****** *** *****
  • Low **** ********* *** ***** **** **** * ****** **** ***** ********** *** **** ****** ** ** ****** *** *****
  • Good **** ********* *** **** **** *******
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