Where Should Students Practise Coding? A Guide to Coding Challenge Sites

One of the best ways to improve at programming is simply to write more programs. Tutorials are useful for introducing a concept, but there comes a point when students need to close the tutorial, look at a problem and work out the solution for themselves.

There is now an enormous range of websites offering coding challenges. LeetCode, HackerRank, Codewars, Exercism, Codeforces and others all provide opportunities to practise programming, but they are designed for surprisingly different purposes. A website that is excellent preparation for a software engineering interview may be a terrible place for a 13-year-old who has just discovered a for loop.

So rather than asking which coding challenge website is best, a better question is:

Which coding challenge website is best for what I am trying to learn?

Quick links

Python Code Lab – designed for students learning to program

I will start with my own resource because it was created to solve a problem I regularly encounter as a Computer Science teacher.

Python Code Lab is designed specifically to help students move from learning Python constructs to independently solving programming problems.

The accompanying Python Code Lab Challenge List contains more than 100 Python challenges divided into Mild, Medium and Spicy difficulty levels. Students can search the challenges, track their progress locally and load challenges directly into the coding environment.

The wider Python Code Lab environment includes text and block-based programming, flowcharts, Parsons problems, step tracing, variables and call-stack views, trace tables, turtle graphics, debugging activities, courses and algorithm practice. Students can therefore approach the same ideas in several different ways rather than simply submitting code to a black-box testing system.

This distinction matters in education.

Sites designed for professional programmers often assume that the user already understands functions, lists, dictionaries, classes, algorithmic complexity and how automated tests work. Python Code Lab deliberately provides a lower entry point.

I see its purpose as helping students reach the stage where they are ready for those larger platforms.

And if students eventually outgrow it, that is a good thing.

Best for: School students, Python beginners, GCSE/IGCSE and early sixth-form programmers, classroom use and building confidence with independent problem solving.

Less suitable for: Advanced competitive programming and intensive technical interview preparation.

Try it: Python Code Lab | Challenge List

LeetCode – the destination for technical interview preparation

If a student asks me which challenge platform is most relevant to eventually applying for software engineering jobs, LeetCode is probably the first one I would show them.

LeetCode focuses heavily on data structures, algorithms and the style of problem solving commonly associated with technical interviews.

It includes structured study plans as well as thousands of individual problems. Particularly useful starting points include:

• Programming Skills – a gentler introduction to implementation-style problems
• LeetCode 75 – a curated set of interview problems
• Top Interview 150 – a larger interview-preparation pathway

This makes LeetCode particularly valuable for students heading towards university Computer Science, internships and software development careers.

It is also why I would not recommend starting there.

A beginner encountering concepts such as sliding windows, dynamic programming, graph traversal or recursive backtracking can quickly conclude that they are bad at programming. In reality, they may simply be attempting problems aimed at candidates preparing for professional technical interviews.

LeetCode becomes much more valuable once a learner already understands fundamental programming and common data structures.

Best for: Data structures and algorithms, university students, internship preparation and technical interviews.

Less suitable for: Absolute beginners, learning programming syntax and learning how complete software applications are built.

Try it: LeetCode

HackerRank – particularly useful for recruitment-style assessment

HackerRank overlaps considerably with LeetCode, but I think its strongest identity is slightly different.

It provides practice organised around languages and topics including Python, Java, C++, SQL, algorithms, data structures and mathematics.

More importantly, HackerRank is closely connected with technical recruitment. Many employers use HackerRank-style assessments or similar timed coding tests as part of their screening process.

That makes HackerRank useful for a student who wants to understand what an online coding assessment might actually feel like.

It is also particularly useful for areas such as SQL that are not always as prominent on traditional algorithmic challenge sites.

Best for: Recruitment tests, assessment practice, SQL, programming language practice and job preparation.

Less suitable for: Very young beginners or students primarily looking for creative programming projects.

Try it: HackerRank

Codewars – coding practice that feels like a game

Codewars takes a rather different approach.

Problems are called kata, borrowing the idea of repeatedly practising techniques until they become fluent. Challenges are ranked from 8 kyu at the beginner end towards 1 kyu at the expert end.

There are thousands of kata covering fundamentals, strings, algorithms, recursion, regular expressions, databases, games and data structures.

One of Codewars’ greatest strengths is what happens after solving a problem.

Students can examine solutions submitted by other programmers. This can be enormously valuable. A learner may produce a perfectly functional 20-line solution and then discover that somebody else has approached the same problem in a completely different way.

Codewars therefore encourages experimentation with the programming language itself rather than only finding the theoretically optimal algorithm.

Its ranking system also gives it a strong game-like quality that some students find highly motivating.

Because many kata are community created, however, challenge style and quality can vary.

Best for: Regular practice, language fluency, short challenges, comparing different solutions and students who enjoy progression systems.

Less suitable for: A carefully sequenced Computer Science curriculum or systematic interview preparation.

Try it: Codewars

Exercism – becoming better at the language itself

Exercism is one of my favourite alternatives because its philosophy is somewhat different again.

Rather than concentrating primarily on solving harder and harder algorithmic puzzles, Exercism focuses heavily on becoming fluent in a programming language.

It supports dozens of programming languages and provides exercises that can be completed in the browser or locally.

More importantly, Exercism combines automated analysis with optional feedback from human mentors. This can encourage an important change in thinking.

The question stops being:

“Does my program work?”

and starts becoming:

“Is this a good way to write this program in Python?”

Those are not the same thing.

A solution can pass every test while still being unnecessarily complicated, difficult to read or poorly structured.

Best for: Improving language fluency, code quality, learning a second programming language and receiving feedback.

Less suitable for: Students whose main objective is technical interview pattern recognition.

Try it: Exercism

freeCodeCamp – better for learning than simply practising

freeCodeCamp belongs on this list, although I would describe it primarily as a learning platform rather than a pure challenge platform.

Its curriculum combines theory, interactive examples, coding exercises, projects and certification pathways.

It covers areas including responsive web design, JavaScript, Python, relational databases, front-end libraries and back-end development.

That makes it much more appropriate than LeetCode for someone asking:

“How do I learn programming?”

rather than:

“How do I practise programming problems?”

It is especially useful for learners interested in web development because it gradually moves from individual concepts into building larger pieces of software.

Best for: Beginners, structured self-study, web development and project-based learning.

Less suitable for: Someone who already knows a language and simply wants a large collection of independent algorithmic challenges.

Try it: freeCodeCamp

Codeforces – when programming becomes a competitive sport

Codeforces takes things considerably further.

This is competitive programming.

Problems are rated by difficulty and tagged with areas such as dynamic programming, graphs, binary search, number theory and combinatorics.

Regular competitions allow programmers around the world to solve problems against the clock and receive ratings based on their performance.

For a strong student who genuinely loves algorithmic problem solving, Codeforces can be fantastic.

It can also be brutal.

Competitive programming increasingly combines programming with mathematics, algorithm design and the ability to recognise sophisticated problem patterns very quickly.

For most school students, I would consider Codeforces an extension rather than a starting point.

Best for: Competitive programmers, very strong problem solvers and students who enjoy algorithms and mathematics.

Less suitable for: Beginners and learners whose priority is general software development.

Try it: Codeforces

AtCoder – another excellent route into competitive programming

AtCoder is another major competitive programming platform, based in Japan but used internationally.

Its competitions include Beginner Contests, Regular Contests, Grand Contests and heuristic competitions.

I would place AtCoder alongside Codeforces for students who discover that solving programming problems competitively is something they genuinely enjoy.

Its problem statements are often precise and its contest structure provides a natural progression from relatively accessible problems towards very advanced algorithmic work.

Best for: Competitive programming and systematic algorithmic problem solving.

Less suitable for: Learning a language from scratch or building application-development skills.

Try it: AtCoder

NeetCode – a useful guide through the LeetCode jungle

NeetCode is worth mentioning because one problem with LeetCode is simply knowing what to solve.

Opening a website containing thousands of programming problems can lead to random practice rather than deliberate learning.

NeetCode approaches interview preparation through structured roadmaps organised around recurring problem-solving patterns such as arrays, two pointers, sliding windows, trees, graphs, backtracking and dynamic programming.

I therefore see NeetCode less as a replacement for LeetCode and more as an excellent guide through it.

For many students, the well-known NeetCode 150 is a much more manageable way to approach interview preparation than simply opening LeetCode and choosing random problems.

Best for: Students who are ready for LeetCode but want a structured route through interview algorithms.

Less suitable for: Complete beginners.

Try it: NeetCode

So which platform should students use?

Perhaps more useful than choosing a winner is thinking about these platforms as a progression.

For my own students, I increasingly see a route something like this:

Python Code Lab -> Codewars or Exercism -> LeetCode Programming Skills -> LeetCode 75

That last part is important.

Coding challenges are not software engineering

Someone can become exceptionally good at LeetCode without necessarily becoming exceptionally good at developing software.

Challenge platforms teach problem decomposition, algorithmic thinking, debugging, syntax, data structures and efficient implementation. These are valuable skills.

They usually do not teach students how to maintain a 20,000-line codebase, structure a large application, use Git with a development team, write documentation, manage a database, design an API, deploy software or work with somebody else’s badly written code.

Students therefore need both experiences.

I would much rather see an aspiring software developer with a reasonable LeetCode record and several genuine projects than somebody who has completed 1,000 algorithm problems but has never built anything substantial.

The right challenge at the right time

The important thing is not finding the hardest possible programming website. It is finding a challenge that sits just beyond what the learner can comfortably do. For a student who has only recently learned selection and iteration, that might be a Mild challenge in Python Code Lab. A few years later, the same student might be implementing a binary tree on LeetCode.

Python Code Lab was built to help students begin that journey in a gentle self-assessed way before they move onto bigger challenges.