10 websites to practice coding problems: Our picks | ZDNet

Whether you’re just starting out as a coder or want to advance your coding skills, tackling programming problems is part of the plan. 

Convenient, free, and even fun, coding problem websites challenge your abilities with individual exercises, friendly challenges, and insightful assessments.

Practicing your coding through these websites may increase your knowledge, build your skills, and prepare you for programming job interviews. 

Top websites for practicing your coding skills

How hard is it to learn coding? Starting from scratch can be difficult, but coding challenges designed to test and advance your skills may help. We rounded up 10 great websites for coding problems and listed them alphabetically for you. 

Each website offers a collection of resources for learning coding or advancing what you already know. 

1. CodeChef

CodeChef lets you choose among thousands of problems to practice skills like sorting, data structures, and dynamic programming. Problems are sortable by difficulty. Code Chef’s practice problems allow you to answer in one of over 50 programming languages as you prepare for its internal or external monthly contests. 

CodeChef offers self-guided learning opportunities and mentoring programs alongside a community of coders, coding bootcamps, and tech certification programs. 

2. Coderbyte

Designed for coding practice and improvement, Coderbyte offers code challenges and courses aimed at helping you prepare for job interviews. 

Coderbyte had over three million solutions with challenges in more than 25 languages. Starter courses in algorithms, JavaScript, Ruby, and Python accompany interview kits and career resources. 

You can sign up for a free challenge and free trial. A monthly subscription to Coderbyte costs $35 and an annual subscription is $150. Both give you access to all of Coderbyte’s resources. 

3. Codewars

Launched in 2012, Codewars provides practice kata, or small coding exercises, that you advance through as you build your skills. Codewars’ kata are available in nearly 60 programming languages and in levels from beginner to advanced.

You can develop your own kata, engage with the Codewars community, and master one or multiple languages in the process. Feedback and creative learning facilitate creative thinking and innovation among Codewars’ users. Codewars offers resources for educators and companies as well. 

4. CodinGame

With more than 25 supported languages, CodinGame provides challenge-based programming training through games, puzzles, and competitions. 

CodinGame’s resources let you build your programming abilities, learn new concepts, and interact with fellow coders through easy, medium, hard, and very hard exercises.

CodeinGame’s leaderboard and prizes earn you recognition from your peers and track your progress. Free live streams, blogs, and discussion forums for developers accompany sourcing, screening, and retention programs for recruiters. 

5. Geektastic

With human-reviewed technical assessments, Geektastic lets companies customize coding challenges for talent acquisition and engineering team training. If you have coding experience, you can join Geektastic’s reviewer community to create and test those challenges — and get paid to review candidates’ performance. 

Code challenges are offered in Java, Python, and PHP. Geektastic also offers skills assessments in Java, Javascript, and basic coding. Joining as a developer comes with no cost, while flexible pricing accommodates businesses of any size. 

6. HackerRank

HackerRank serves as a technical interview platform, but also provides coding practice to over 18 million users. Challenges offered by HackerRank cover topics including algorithms, Java, Python, Ruby, and data structures. 

HackerRank’s challenges allow you to test your code, debug it, and win one of its sprint, company, language, or timed challenges. You can also earn certifications in specific skills or complete interview preparation kits. Pricing ranges from $25/month for interview content to $819/month team subscriptions.

7. LeetCode

LeetCode provides more than 2,250 practice problems to its programmer community. Individual challenges in topics like algorithms, database structures, and dynamic programming accompany entire study plans. 

LeetCode’s programming skills study plan integrates three modules offered at easy, medium, or hard difficulty levels. LeetCode supports 14 programming languages and houses a playground tool to help you test, debug, and write code. 

Sign-up is free. LeetCode Premium offers access to additional tools and premium content for a monthly subscription of $35 or an annual fee of $159. 

8. Project Euler

Named for mathematician Leonhard Euler, Project Euler began in 2001. Recent and archival content is available for registered users at no cost. 

Project Euler offers computational programming problems combining mathematics with computer and programming skills. With 108 programming languages and more than one million users, Project Euler provides problems with varying difficulty.

9. SPOJ

Sphere Online Judge, or SPOJ, trains users to code and build efficient algorithms through more than 20,000 practice problems. Scoring categories for problems include challenges, tutorials, and riddles. Rankings and a status board accompany running contests that support more than 45 programming languages and compilers. 

SPOJ offers a flexible testing system to automatically assess user-submitted programs. Users can design their own contests or take part in an online course at all programming levels, but it is ideal for students.

10. TopCoder

TopCoder’s community of designers, developers, data scientists, and competitive programmers build their skills, show their expertise, and earn money as they improve their coding abilities. TopCoder pays individuals for their work, sells it to corporate clients, and hosts competitions designed to highlight top coding talent worldwide.

Customers use TopCoder to hire freelancers on-demand, set challenges for the coding community, and find teams for projects.

This article was reviewed by Monali Mirel Chuatico

In 2019, Monali Mirel Chuatico graduated with her bachelor’s in computer science, which gave her the foundation that she needed to excel in roles such as data engineer, front-end developer, UX designer, and computer science instructor.

Monali is currently a data engineer at Mission Lane. As a data analytics captain at a nonprofit called COOP Careers, Monali helps new grads and young professionals overcome underemployment by teaching them data analytics tools and mentoring them on their professional development journey.

Monali is passionate about implementing creative solutions, building community, advocating for mental health, empowering women, and educating youth. Monali’s goal is to gain more experience in her field, expand her skill set, and do meaningful work that will positively impact the world.

Monali Mirel Chuatico is a paid member of the Red Ventures Education Integrity Network. 

Last reviewed April 21, 2022.