BuiltWith Technology Profiler
Find out what the website you are visiting is built with using this extension.
Disable cookies for current domain.
Live HTTP Headers
Monitor all HTTP/HTTPs traffic from your browser.
Use Redux DevTools in the DevTools
Browse JSON like you do it in Finder.
PDF API HTML5
Click on any HTML element to get the font info in a popup
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
View all HTTP Requests and Responses sent between the Web browser and the Web server.
Firebug Lite for Opera 15+
Quickly view the HTTP headers of the current tab.
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!
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, ...
Google Analytics Debugger
A browser extension for debugging Google Analytics tracking code
Right Click Validator
Right click on any webpage to validate it using the W3 NUValidator service.
SEO Analysis with Seoptimer
Just one click to SEO Analysis with Seoptimer
Shows the response times and uptime of a desired server. Useful to see how performs internet or a wireless access point.
Picture in Play
Indicates whether the `picture` element is in use on a page.
Get Thumbnails or Image to video YouTube
Faça miniaturas ou imagens de vídeos do YouTube
Remove cookie(s) for the current domain
Remove cookie(s) for the current site with just one click
Website Analysis & SEO Tool
Website SEO audit tool that provides website analysis in SEO, performance, validity, security, accessibility and other criteria.
A small extension to validate the markup of current tab
This extension allows you to add your own custom website specific CSS style sheets.
Edit the Page
Toggles the 'Design Mode' so that you can edit the contents of the page.
WordPress Theme and Plugins Detector
This tool detects theme and plugins used on WordPress sites and displays information about them.
This will take the URL of the current tab and send it to PageSpeed Insights for a web performance analysis.
ChroPath for Opera
AutonomIQ offers a developers platform ChroPath to generate and validate unique selectors like relative xpath with iframe support
Website Color Changer
Extends the Developer Tools, adding a sidebar for colors manipulation
Block Yourself from Analytics
Block your Google Analytics™ activity for the websites you own, no more false stats.
This extension predicts rating changes for Codeforces. It shows approximate deltas during and after the contest.