# SimpleModifyHeaders V 1.3 Extension for firefox . The extension rewrite the headers based on a rules table. The rules table contains lines with the following parameters : - action : add, modify or delete a header field - header field name - header field value - comment : a comment - apply on : "request" if the modification apply on the request headers or "response" if the modification apply on the response headers - status : on if the modification is active , off otherwise We can choose the urls on which the modifications applies by modifying the url pattern. The url pattern must follow the syntaxe define by https://developer.chrome.com/extensions/match_patterns . Putting an empty string on the field will select all urls. To save and apply the modification , you need to click on the save button It's possible to: - export the configuration in a file (json format) - import the configuration from a file , it support the format of the Modifyheaders plugin The extension can be start and stop via the button on the top right. The code is opensource under Mozilla Public License 2.0