Custom Style Script
Disable cookies for current domain.
Modify Header Value
Add, modify or remove a header for any request on desired domains.
Use Redux DevTools in the DevTools
Firebug Lite for Opera 15+
Live HTTP Headers
Monitor all HTTP/HTTPs traffic from your browser.
Browserling - Cross-browser testing
Cross-browser test websites in the most popular browsers such as Internet Explorer, Edge, Chrome, Firefox, Safari and Opera. Try for free!
Right Click Validator
Right click on any webpage to validate it using the W3 NUValidator service.
Click on any HTML element to get the font info in a popup
Live editor for CSS and LESS - Magic CSS
Live preview of CSS/LESS code with an in-page editor. Autocomplete, convert LESS to CSS, beautify, minify, CSS reloader, linter, ...
Edit the Page
Toggles the 'Design Mode' so that you can edit the contents of the page.
Picture in Play
Indicates whether the `picture` element is in use on a page.
Browse JSON like you do it in Finder.
ChroPath for Opera
AutonomIQ offers a developers platform ChroPath to generate and validate unique selectors like relative xpath with iframe support
This extension allows you to add your own custom website specific CSS style sheets.
View all HTTP Requests and Responses sent between the Web browser and the Web server.
Corser - Authorize CORS requests
Cross-browser extension for authorizing cross-origin resource sharing (CORS) requests. This extension can be installed on browsers supporting the WebExtensions API (https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions) It intercepts all CORS requests and responses headers, and records/adds/changes their values so as to authorized unauthorized CORS requests. Use this extension only for testing purposes
This will take the URL of the current tab and send it to PageSpeed Insights for a web performance analysis.
WordPress Theme and Plugins Detector
This tool detects theme and plugins used on WordPress sites and displays information about them.
SEO Analysis with Seoptimer
Just one click to SEO Analysis with Seoptimer
Get Thumbnails or Image to video YouTube
Make thumbnail previews or images from YouTube videos
Website Analysis & SEO Tool
Website SEO audit tool that provides website analysis in SEO, performance, validity, security, accessibility and other criteria.
Edit with Adobe Photoshop
Adds a context menu item to send image links directly to Adobe Photoshop photo editor
Quickly view the HTTP headers of the current tab.
Google Analytics Debugger
A browser extension for debugging Google Analytics tracking code
The simplest extension for working with web fonts
Block Yourself from Analytics
Block your Google Analytics™ activity for the websites you own, no more false stats.
OCR - Image Reader
A powerful optical character recognition (OCR) extension to capture and convert images to text
Website Color Changer
Extends the Developer Tools, adding a sidebar for colors manipulation