Modify Header Value
Add, modify or remove a header for any request on desired domains.
Right Click Validator
Right click on any webpage to validate it using the W3 NUValidator service.
Disable cookies for current domain.
PDF API HTML5
Live HTTP Headers
Monitor all HTTP/HTTPs traffic from your browser.
Firebug Lite for Opera 15+
GitHub code tree on steroids
Edit the Page
Toggles the 'Design Mode' so that you can edit the contents of the page.
Quickly view the HTTP headers of the current tab.
Click on any HTML element to get the font info in a popup
View all HTTP Requests and Responses sent between the Web browser and the Web server.
Browse JSON like you do it in Finder.
A webpage form filler that populates context specific random test data into forms elements.
Edit with Adobe Photoshop
Adds a context menu item to send image links directly to Adobe Photoshop photo editor
This extension allows you to add your own custom website specific CSS style sheets.
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, ...
Use Redux DevTools in the DevTools
Google Analytics Debugger
A browser extension for debugging Google Analytics tracking code
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
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
Web Developer Checklist
Analyses any web page for violations of best practices
Selenium Page Object Generator
A nimble and flexible Selenium Page Object Model generator to improve agile testing process velocity.
Website Analysis & SEO Tool
Website SEO audit tool that provides website analysis in SEO, performance, validity, security, accessibility and other criteria.
Colored favicons for Salesforce
Make the favicon in different color based on which salesforce instance your are loggen into.
Open in GIMP photo editor
Adds a context menu item to send images directly to GIMP photo editor
WordPress Theme and Plugins Detector
This tool detects theme and plugins used on WordPress sites and displays information about them.
Remove cookie(s) for the current domain
Remove cookie(s) for the current site with just one click