PDF API HTML5
BuiltWith Technology Profiler
Find out what the website you are visiting is built with using this extension.
Picture in Play
Indicates whether the `picture` element is in use on a page.
Disable cookies for current domain.
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!
Firebug Lite for Opera 15+
Live HTTP Headers
Monitor all HTTP/HTTPs traffic from your browser.
Modify Header Value
Add, modify or remove a header for any request on desired domains.
Browse JSON like you do it in Finder.
Edit the Page
Toggles the 'Design Mode' so that you can edit the contents of the page.
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, ...
Website Analysis & SEO Tool
Website SEO audit tool that provides website analysis in SEO, performance, validity, security, accessibility and other criteria.
This extension allows you to add your own custom website specific CSS style sheets.
Shows the response times and uptime of a desired server. Useful to see how performs internet or a wireless access point.
Website Color Changer
Extends the Developer Tools, adding a sidebar for colors manipulation
Google Analytics Debugger
A browser extension for debugging Google Analytics tracking code
View all HTTP Requests and Responses sent between the Web browser and the Web server.
This extension predicts rating changes for Codeforces. It shows approximate deltas during and after the contest.
Edit with Adobe Photoshop
Adds a context menu item to send image links directly to Adobe Photoshop photo editor
A browser extension that brings a new GitHub experience
WordPress Theme and Plugins Detector
This tool detects theme and plugins used on WordPress sites and displays information about them.
OCR - Image Reader
A powerful optical character recognition (OCR) extension to capture and convert images to text
Nextsense XML Signing Component
Signing XML document.
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
Quickly view the HTTP headers of the current tab.
ChroPath for Opera
AutonomIQ offers a developers platform ChroPath to generate and validate unique selectors like relative xpath with iframe support
Get Thumbnails or Image to video YouTube
Make thumbnail previews or images from YouTube videos
Web Developer Checklist
Analyses any web page for violations of best practices