Here’s my collection of handy links, most of which are useful to Web designers and developers. Because I am also a musician, there are also some handy links to MIDI resources for vocal music.
Shows a URL at multiple resolutions, all live.
Guidelines, evaluation for mobile-friendly sites.
Mobile Web Design checklist
Beginner’s Guide to Responsive Web Design (RWD)
Can I use HTML/CSS/JS now?
Comprehensive CSS Reference for Statements / Attributes
CSS Specificity Graph Generator
Beautify, minify, format, or compress CSS, JS, JSON, PHP
CSS Statistics for a site
Test for errors and style issues
Excellent curated collection of top Web developer links
Usability in User Interface Design (pointers by Nielsen)
Tool for creating and editing color palettes (by me!)
Color tints and tones and mixes.
Background Image Generator
Generate background patterns
Curated font pairs for Google Fonts.
Robert Bringhurst / typography for Web
Complete list of HTML Character Entities
Typographic Symbols (HTML)
Like CanIUse for Web fonts
Google Closure Compiler (and ES6-to-ES5 transpiler)
Babel ES6-to-ES5 transpiler
Directory of JS libraries, frameworks, plugins.
jQuery Plugin directory (curated)
Interactive examples for learning ES6
WordPress Developer’s Codex
Best Practices in WordPress Development
Excellent WordPress security checklist
Miscellaneous Tools & Articles
Network tools, HTML stuff
Tools for .htaccess files
Check Google PageRank for pages
Excellent set of .htaccess functions
Free resources for Web Designers
Web Developer Article Feeds
Can I Stream It? Essential tool for cord-cutters (like me)!
SETI at Home: join my team AstroScum (team number 747680) and help us find aliens before they find us!
1 million+ free-to-use images from British Library
Weight, Calorie, BMI calculations
Free graph paper templates
Blank sheet music templates
Huge resource for scores and MIDIs.
MIDI files for Choral Singing
Catholic music: hundreds of nicely typeset scores.
Music scores (open source)