Last updated: June 2026. Written by Josh Hutcheson, OnlineCourseing editor. See our review methodology.
QUICK VERDICT
Bottom line: For most people, Master the Coding Interview: Data Structures + Algorithms (Udemy) is the best starting point — it teaches the patterns interviewers actually test, at a price that’s usually under $20 on sale. If you want academic rigor for free, Princeton’s Algorithms, Part I on Coursera is unmatched.
- Best for interviews: Master the Coding Interview (Udemy) or Grokking the Coding Interview Patterns (Educative)
- Best free / academic: Algorithms, Part I (Princeton, Coursera)
- Skip if: you only need a quick refresher — a YouTube playlist will do
Data structures and algorithms (DSA) are the foundation of every technical interview and most serious software work. But “best DSA course” means different things depending on whether you’re cramming for a FAANG interview, working through a CS degree, or learning the fundamentals for the first time. We tested the leading options and ranked them by who they actually serve. Every course below was verified live and current as of June 2026, with its rating pulled the same day.
What are data structures and algorithms?
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A data structure is a way of organizing information so it can be used efficiently — arrays, linked lists, hash tables, stacks, queues, trees, and graphs are the common ones. An algorithm is a step-by-step procedure for solving a problem with that data, such as searching, sorting, or finding the shortest path. The two are inseparable: choosing the right structure makes the algorithm fast, and the wrong one makes it slow. Interviewers test DSA because it reveals whether you can reason about efficiency (Big-O), not just write code that runs. That’s why a good DSA course spends as much time on when and why to use a structure as on how to implement it.
HOW WE PICKED
We prioritized courses that (1) cover the full core — Big-O, the standard structures, and the major algorithm classes; (2) carry a strong rating from a large number of students, or genuine academic authority; and (3) are actively maintained. We loaded every course page on the day of writing to confirm it’s live and to pull its current rating and last-updated date, because course quality decays and stale listicles keep recommending dead or outdated courses. Where the best option is free, we say so even though it earns us nothing.
AT A GLANCE
| Course | Best for | Platform | Rating |
|---|---|---|---|
| Master the Coding Interview: DS + Algorithms | Best overall / interviews | Udemy | 4.6 (40,000+) |
| Algorithms, Part I | Best free / academic | Coursera (Princeton) | 4.9 |
| Grokking the Coding Interview Patterns | Pattern-based interview prep | Educative | Editor’s pick |
| Data Structures and Algorithms Specialization | Structured university path | Coursera (UC San Diego) | 4.6 |
| JavaScript Algorithms and Data Structures Masterclass | Best for JavaScript devs | Udemy | 4.7 (31,000+) |
1. Master the Coding Interview: Data Structures + Algorithms — Best Overall
Andrei Neagoie’s course is the one we’d hand to most people. It rated 4.6 from over 40,000 students and was last updated 3/2026, so the content is current. Rather than drilling every textbook structure, it focuses on what coding interviews actually test: Big-O analysis, the core structures (arrays, hash tables, trees, graphs), and the algorithmic patterns (recursion, sorting, dynamic programming) that recur across questions. It’s language-flexible, so you can follow along in whatever you interview in.
Who it’s for: anyone preparing for technical interviews who wants one comprehensive, affordable course. Watch for: on sale it’s usually under $20, but the list price is much higher — never pay full price for a Udemy course, a sale is always around the corner.
2. Algorithms, Part I (Princeton) — Best Free & Academic
If you want the rigorous, university-grade treatment and don’t mind a heavier workload, Princeton’s Algorithms, Part I — taught by Robert Sedgewick and Kevin Wayne — is the gold standard, and it’s free to audit. It rated 4.9 on Coursera and goes deep on the analysis and implementation of fundamental structures and sorting/searching algorithms in Java. Part II continues into graphs and strings.
Who it’s for: CS students and self-learners who want depth and theory, not just interview tricks. Watch for: it’s demanding and Java-based; expect real time on the programming assignments.
3. Grokking the Coding Interview Patterns (Educative) — Best Pattern-Based Prep
Educative’s Grokking series takes a different angle: instead of teaching structures in isolation, it organizes interview questions into recurring patterns (sliding window, two pointers, fast and slow pointers, and so on), so you learn to recognize which approach a new problem calls for. It’s text-based and interactive — you read and run code in the browser rather than watching video, which many people find faster.
Who it’s for: developers who’ve seen the basics and want to get efficient at pattern recognition before interviews. Watch for: it’s a subscription (typically billed monthly or annually), so it’s best when you’ll use it intensively over a few weeks.
4. Data Structures and Algorithms Specialization (UC San Diego) — Best Structured Path
This Coursera specialization rated 4.6 and runs across several courses, taking you from the basics through graph algorithms, NP-complete problems, and a genome-assembly capstone. It’s the closest thing to a structured university sequence you can complete at your own pace, and it includes a strong dose of implementation practice.
Who it’s for: learners who want a guided, multi-course journey and a shareable certificate. Watch for: it’s a multi-month commitment on a Coursera subscription; don’t start it if you only need interview cramming.
5. JavaScript Algorithms and Data Structures Masterclass (Colt Steele) — Best for JavaScript Devs
If you work in JavaScript, Colt Steele’s masterclass is the natural fit. It rated 4.7 from over 31,000 students and was updated 1/2026. Steele is a well-regarded instructor known for clear explanations, and the course covers Big-O, the common structures, and classic algorithms entirely in JavaScript with plenty of problem-solving practice.
Who it’s for: front-end and full-stack JS developers who want DSA taught in their own language. Watch for: as with any Udemy course, wait for the sale price.
Best free option: freeCodeCamp & MIT OpenCourseWare
If budget is the deciding factor and you’re self-disciplined, you don’t strictly need a paid course at all. freeCodeCamp publishes full-length DSA courses on YouTube (often 5 to 10+ hours) in multiple languages, and MIT OpenCourseWare offers the legendary Introduction to Algorithms (6.006) lectures and problem sets for free. Neither earns us a commission, and we’re recommending them anyway because they’re genuinely excellent — the trade-off is that you get no graded feedback, no certificate, and no structured accountability. Pair them with a problem-solving site and you have a complete free path. Most people still benefit from a paid course’s structure, but it’s an honest option worth knowing about.
Free vs paid: which should you choose?
Go free if you learn well on your own, don’t need a certificate, and are mainly filling knowledge gaps — Princeton’s audit track, freeCodeCamp, and MIT OCW will take you a long way at zero cost. Go paid if you want a guided sequence, interview-specific pattern training, graded practice, or the accountability of having spent money. The paid options here are inexpensive relative to the salary bump a passed technical interview delivers: a sub-$20 Udemy course or a month of an Educative or Coursera subscription is a rounding error against a single engineering paycheck. The real cost is your time, so pick the format you’ll actually finish.
How to choose the right DSA course
Match the course to your goal, not the other way around:
- Interviewing soon? Lead with a patterns-and-practice course (Master the Coding Interview or Grokking) and pair it with active problem-solving on a judge like LeetCode.
- Building fundamentals? The Princeton or UC San Diego options give you the theory that makes everything else click.
- Tied to a language? Pick the course taught in the language you’ll actually use day to day.
Whatever you choose, the single biggest predictor of success isn’t the course — it’s how many problems you solve yourself. Treat the course as the map and the practice as the miles.
Frequently asked questions
What is the best data structures and algorithms course?
For most people, Master the Coding Interview: Data Structures + Algorithms on Udemy is the best all-around choice — it’s comprehensive, interview-focused, and usually under $20 on sale. For free academic depth, Princeton’s Algorithms, Part I on Coursera is the strongest option.
Can I learn data structures and algorithms for free?
Yes. Princeton’s Algorithms, Part I and Part II are free to audit on Coursera, and there are excellent free YouTube series. You’d pay only if you want a certificate, graded assignments, or a structured paid platform.
Which language should I learn DSA in?
Use the language you’ll interview or work in. The concepts transfer across languages, but practicing in your primary language saves friction. JavaScript developers can use Colt Steele’s masterclass; the Princeton course is in Java.
How long does it take to learn data structures and algorithms?
A focused learner can cover the core material in four to eight weeks of consistent study, but interview-readiness depends mostly on how many practice problems you work through, which often takes a few months.
Are paid DSA courses worth it over free ones?
Paid courses are worth it mainly for structure, graded practice, and interview-specific pattern training. If you’re disciplined, free resources can get you most of the way; if you want a guided path and accountability, the paid options earn their cost.