HTML COLOURS – Online Colour tools
The HTML online colour picker allows the user to create any colour imaginable and returns a hexadecimal value for the colour.
The HTML Colour Names page offers a list of colours and their respective names. The use of the given colour names is compatible with all browsers.
HTML Characters – Online Character and Symbol HTML codes
W3C Online Arrow Symbols e.g. ↛ ↥ ↱ ⇔⇼ – URL outdated – previously – http://www.w3schools.com/charsets/ref_utf_arrows.as
The most recent editions to online characters includes
Emoji Skin Tones, select the skin tone of your emoji
Online Code Validators
W3C Validator Overview
The W3C Validator Overview page offers a list of validators and other online tools that can be used to determine the health of your code and site.
Overview of W3C Validators and other useful tools
HTML and XHTML Validator
The HTML and XHTML validator validates all HTML and XHTML prior to HTML 5!
HTML, XHTML validator
The CSS Validator, will validate all CSS prior to version 3!
Mobile Website Validator
The mobile website OK tool, will validate your html and xhtml, plus page and image sizes. The W3 version no longer works, however you might like to try the google version.
Google mobile-friendly test
Website Link Checker
The link checker will check any url(page) for broken links, remember to scroll to the bottom of the page for results.
Link Checker – Checks for broken links, URL’s that go nowhere, missing pages ect.