freeCodeCamp JavaScript Algorithms & Data Structures
Self-paced
Yes
HTML/CSS basics
Free interactive curriculum + certification. Hundreds of in-browser challenges covering JS, ES6, basic data structures, OOP, FP, algorithms.
What you will learn:
- ES6+ JavaScript syntax
- Basic algorithms (string manipulation, sorting)
- Data structures (arrays, objects, maps, sets)
- Object-oriented and functional programming
Who it is for: Self-taught developers, bootcamp grads patching DSA gaps, anyone preparing for junior dev interviews.
Honest take: The single best free JS+DSA prep on the internet. Do every challenge — the certification holds weight with hiring managers.