Useful Resources

Colour Schemes

Adobe Colour Wheel - Manually choose colours or upload an image and generate a colour scheme based on predominant colours.
Paletton Colour Scheme Designer - Manually select a base colour and view recommended colour schemes. You can also see how the colours look in example websites.

Pixaby - My go to site for graphics. All images are licensed under Creative Commons CC0 license meaning you can use them however you want, even commercially! Over 1.5 million images.
Unsplash - Another website where images are free to use and covered by CC0. Over 300,000 images.
Pexels - Another website where images are free to use and covered by CC0. Over 40,000 images, some of which are actually sourced from Pixabay.
freepik - A good place to look if trying to find icons, this site contains a mixture or CC0, non-commerical, and licensed images.

HTML Validator - Will identify errors and bad practice in you HTML code. Works by providing a URL, file upload, or pasting code.
CSS Validator - Will identify errors and bad practice in you HTML code. Works by providing a URL, file upload, or pasting code.
JavaScript Validator - Will validate your code to an acceptable level.
JavaScript Validator (Strict) - Will identify errors in your code. This is a stricter validator meaning it will be much more picky in terms of the practices used. When editing a JS file in the Brackets code editor it validates it using JSLint.
WAVE Accessibility - Enter a URL and it will tell you how accessible your site is based on your code and colour scheme.
PageSpeeds - The Google PageSpeed tool takes a URL and provides you with an analysis of performance with tips on which areas of your code could be improved.

Can I Use - Not all parts of front-end technologies (JS, CSS, ect) are supported by every browser. For example, some parts of the CSS3 specification are not supported by older browsers. Enter a feature and the site will tell you which browsers support the feature. As a rule of thumb we should support the current browser version and the previous 3, though the more the better.