mitmproxy is your swiss-army knife for debugging, testing, privacy measurements, and penetration testing. It can be used to intercept, inspect, modify and replay web traffic such as HTTP/1, HTTP/2, WebSockets, or any other SSL/TLS-protected protocols. You can prettify and decode a variety of message types ranging from HTML to Protobuf, intercept specific messages on-the-fly, modify them before they reach their destination, and replay them to a client or server later on.

This PHP library allows creating functional webdriver tests with PHP.

Live interactive cross-browser testing

Goutte is a screen scraping and web crawling library for PHP.

Goutte provides a nice API to crawl websites and extract data from the HTML/XML responses.

Microsoft provides virtual machine disk images to facilitate website testing in multiple versions of IE, regardless of the host operating system. With a single command, you can have IE6, IE7, IE8, IE9, IE10, IE11 and MSEdge running in separate virtual machines.

Skipfish is an active web application security reconnaissance tool. It prepares an interactive sitemap for the targeted site by carrying out a recursive crawl and dictionary-based probes. The resulting map is then annotated with the output from a number of active (but hopefully non-disruptive) security checks. The final report generated by the tool is meant to serve as a foundation for professional web application security assessments.

A simple, modern and intuitive unit testing framework for PHP!

Test Your Website at Different Screen Resolutions

A passive reconnaissance tool inside the DOM (experimental)

Wapiti allows you to audit the security of your web applications.

It performs "black-box" scans, i.e. it does not study the source code of the application but will scans the webpages of the deployed webapp, looking for scripts and forms where it can inject data.

Once it gets this list, Wapiti acts like a fuzzer, injecting payloads to see if a script is vulnerable.

Nikto is an Open Source (GPL) web server scanner which performs comprehensive tests against web servers for multiple items, including over 6500 potentially dangerous files/CGIs, checks for outdated versions of over 1250 servers, and version specific problems on over 270 servers. It also checks for server configuration items such as the presence of multiple index files, HTTP server options, and will attempt to identify installed web servers and software. Scan items and plugins are frequently updated and can be automatically updated.

To help you find the perfect CSS-reset styles, CSSresetr lets you try all the best CSS Resets on a variety of web pages – even your own.

Run a free website speed test from multiple locations around the globe using real browsers (IE and Chrome) and at real consumer connection speeds.

A Conditional Loader For Your Polyfills!

Ever needed custom formatted sample / test data, like, bad? Well, that's the idea of this script. It's a free, open source tool written in JavaScript, PHP and MySQL that lets you quickly generate large volumes of custom data in a variety of formats for use in testing software, populating databases, and... so on and so forth.

Pages compete head-to-head in your browser to see who's fastest!

What PHPMD does is: It takes a given PHP source code base and look for several potential problems within that source. These problems can be things like: Possible bugs, Suboptimal code, Overcomplicated expressions, Unused parameters, methods, properties

JS Bin is a tool for experimenting with web languages. In particular HTML, CSS and JavaScript, but JS Bin also supports other languages too (like Markdown, Jade and Sass).
JS Bin is ultimately a code sharing site.

The mobiReady testing tool evaluates mobile-readiness using industry best practices & standards.

Landing page optimization for your mocks and wireframes.

Fivesecondtest helps you fine tune your landing pages and calls
to action by analyzing the most prominent elements of your design.