Here is a list of seven 7 Free sites for Front end developers you probably didn’t know that existed. I hope it will be useful.
Input Credits : Csaba Kissi
1. AppFlowy
AppFlowy is an open-source alternative to Notion. You are in charge of your data and customization. https://appflowy.io

2. BubblesJs
BubblesJS Create cross-connected charts like line charts, bar charts, filters, tables, and dashboards in minutes. https://bubblesjs.com

3. Swiffy Slider
Swiffy Slider Responsive and Mobile Touch Carousel. CSS and javascript responsive slider and carousel – lightweight and fast https://swiffyslider.com

4.EmojiMix
emojimix by Tikolu Combine two emojis into one. Thousands of combinations are available. https://tikolu.net/emojimix/

5. JoyJS
JOY.JS make happy little programs https://ncase.me/joy/

6. Tiny UI

Tiny UI Toggle Toggle the state of a UI element to easily create components e.g. collapse, accordion, tabs, dropdown, dialog/modal. https://nigelotoole.github.io/tiny-ui-toggle/
7.Runno

Runno Make your code samples Runno. Paste some code into the textbox, set your runtime, and then copy the iframe into your website. Now you’ve got a snippet of code that someone can run and edit! https://runno.dev