Web Design & Development Tools

What's My Browser - a useful site for directing people to when you need to know what browser they are using.

Search Code - a search engine for code.

Show the Docs - find the relevant docs for your code.

Stat My Web

Dirty Markup Formatter

Online Diff Checker

Save loading time, use a content delivery network (CDN) for common files. You can find a whole bunch of public CDNs here.

Considering trying this service: Design Contest - where professional graphic designers compete for your business.

Placeholder Images

Ever need a placeholder image, looking for something a little different. Here is a good list I found of alternate placeholder image services.

Favicons

6 Handy, Free Icon & Favicon Editors

Favicon Generator

Testing Website Performance

Pingdom Tools

Web Page Analyzer

WebSitePulse

GTmetrix

WebPagetest

YSlow

Pagespeed Insights

Responinator

Find out what your machine is running

Every wonder what technologies a site was built with? Use the BuiltWith tool.

Security

AbuseIPDB is an IP address blacklist for webmasters and sysadmins to report IP addresses engaging in abusive behavior on their networks.

Wireframes, Sketchs, and Front-End Designs

There are several great printable templates available for planning your website design. Here are the ones I found most useful.

Sneekpeekit - Printable Sketch Sheets

I recommend learning about the Visual Vocabulary from Jesse James Garrett. The website has detailed information on how to describe information architecture and interaction design. (The book is also a good read.)

Zurb has a set of responsive sketch sheets and a good article on how to use them when planning your responsive design.

Inspiration Hut also has a set of printable papers.

960grid has several printable sketch sheets; their sheets have 12 or 16 columns in them.

Paper prototyping helper

Paper-based Mediums for Designers, Free PDF Templates and Wireframes 

UI Print

This page contains information I gathered and thought were very useful. See more tools.

Just to let you know, this page was last updated Friday, Nov 27 20