Patterninja - Create patterns online
Adobe Photoshop - Adobe Photoshop is a webtop application for editing images and photos online.
Doodad.dev's Pattern Generator - A free tool for creating unique, royalty-free, repeatable patterns.
Paaatterns - Free collection of beautiful patterns for all vector formats
SVG Stripe Generator - SVG Stripe Generator is an easy-to-use tool that enables you to create unlimited stripes and then download them to the device.
Talent Pool by Minty - Reach award-winning illustrators for your projects