Set of websites which offer illustrations in different styles for free to be used in different designs specially in applications and websites (it's helpful to using in user interface design) All websites links here: 1. https://opendoodles.com 2. https://humaaans.com 3. https://undraw.co/illustrations 4. https://iradesign.io 5. https://drawkit.io 6. https://freepik.com 7. https://icons8.com/ouch/ 8. https://pngtree.com 9. https://wannapik.com 10. https://illlustrations.co 11. https://absurd.design 12. https://lukaszadam.com/illustrations