This extension displays traffic statistics for the current page as determined by Alexa. Information — like page views, bounce rate, and average time on site — appears in the lower-right corner of the web page.
BetterSource shows the document source of a web page in a new tab with line numbers and color syntax highlighting.
BuiltWith is a website profiler tool. Upon looking up a page, BuiltWith returns all the technologies it can find on the page. Its purpose is to help developers, researchers, and designers discover what technologies web pages are using, so they can decide what technologies to implement in turn.
Coda Notes gives you a full suite of tools to visually communicate web ideas in Safari. Use a pen tool to scribble notes, highlight areas, erase mistakes, tack on sticky notes, even change editable text directly on a web page. Then send it off as a screenshot.
Slice Factory
Firebug is a tool to help you develop and debug HTML, Javascript and CSS. Click on the Firebug Lite for Safari button while you browse, and instantly edit, debug and monitor the web page you are viewing.
A quick and easy tool for free-writing CSS into any website. Great for making quick fixes or testing out new ideas.
Lorem Ipsum adds context menus that allow you to easily generate Lorem Ipsum text and insert it into text fields and text area form elements.
MeasureIt lets you draw a ruler on any web page to check the width, height, or alignment of page elements in pixels.
This extension adds a toolbar that allows you to resize the Safari window to six different sizes, including full screen. You can also right-click to resize the window.
This extension examines the webpage you're on using W3C Unicorn, the W3C's validator. Click on the toolbar button to see the results of HTML and CSS validators.
Jerome Danthinne
The Validator extension checks the validity of your (X)HTML code, CSS styles, and RSS feed using W3C Validators and optionally displays the count of errors and warnings found in the badge.