Codioful Great advanced gradient generator allowing multiple gradients, blend modes, size, position and full screen view.
Color Gradient Generator Choose a gradient and customize in numerous ways. Uses gradient algorithms to create good-looking and well-balanced gradients. Simple but good.
Colorleap Generate colour palettes based on time period.
Cool Backgrounds A range of different background inc. animations.
Coolors One of the best ways to generate a colour palette.
Couleur.io Great way to build colour schemes quickly in both dark and light modes.
AnimatiSS Quickly browse and copy the CSS for a range of different animations. Unlike animate.css you don't have download the whole set, only the animations you use.
Animatize.com Great way to create animations by dragging your mouse accross the screen.
AnimXYZ Utility class based animations with CSS variables. "The Tailwind CSS for animations".
CSS3 Animation Cheatsheet Nice little selection of animations along with some simple instructions to set scroll trigger with JQuery.
Cubic Bezier Generator Interactive app for generating bezier curves for CSS transitions. Other https://www.cssportal.com/css-generators.php and resources here.
CubicBezier.com One of the better cubic bezier tools I've found.
Finisher header animations Tool to quickly create header animations using a small js library. You can also slant the header as needed.
Nice Waves Generates highly customizable wave animations using JS and SVG.
Scroll Btween JS library to animate objects on scrolling.
Transition CSS Another CSS transition library with cool page transitions. Very easy to set up. Link to the external file then add an attribute to the HTML element you wish to animate. A bookmarklet even allows setting animations on external sites.
Hibiki HTML An easy-to-use web framework for creating modern front-end applications. There is no JavaScript stack to set up, no boilerplate/scaffolding, no build tools to download and run, and no need to be a JavaScript expert.
Headlime Headlime uses AI to create copy and limited design for websites.
HTML Shell Quickly customize and generate HTML code for a page.
Page Res screenshot generator A quick and easy to use CLI tool to get screenshots from a url in various resolutions. Powerful. Node JS.
Pollan System of design tokens using CSS variables to build any project.
Smarty Names AI for generating and finding available URL's for new websites.
Text cleaner “The main purpose of this utility is to unformat a formatted text and remove all unmeaningful characters which are often present in texts that were copied directly from word processors, web pages, PDFs, client briefs, and e-mails.”
Font Squirrel Aside from a huge range of fonts you can convert any font file into woff and woff2 formats.
UI Libraries
Beer CSS A simple way to explore and use Material design.
Copy Paste CSS Quickly copy CSS for buttons, box shadows, form inputs, colour palettes and emoji.
CSSUI Another library, this is pure CSS, to quickly build complicated components like sliders, dropdowns, accordians etc..
UI Buttons Amazing collection of button effects, easy to copy and use.
UIVERSE The uiverse is a library of buttons, checkboxes, toggle switches, cards, loaders and input. The effects are better than average and yoou can customize on screen before grabbing the code. Excellent resourse.
Website Examples
THe Body Coach Great use of line and video. A beautiful site.