Practice Sites

The best platforms to practice coding, prepare for interviews, and compete with developers worldwide.

LeetCode

The go-to platform for technical interview preparation with 2500+ problems.

Interview Prep

All Levels

Free

Premium

Company-specific questions
Contest weekly
Discussion forums
Premium interview tracks

HackerRank

Practice coding, prepare for interviews, and get hired.

Interview Prep

All Levels

Free

Premium

Skill certifications
Company challenges
Interview kit
Multi-language support

Codeforces

Competitive programming platform with regular contests and a strong community.

Competitive

Intermediate-Advanced

Free

Live contests
Rating system
Problem archive
Virtual contests

Codewars

Achieve mastery through challenges. Train on kata in various languages.

Practice

All Levels

Free

8 kyu to 1 dan ranking
Community kata
40+ languages
Discourse discussion

Exercism

Code practice and mentorship for everyone. Level up your skills.

Learning

Beginner-Intermediate

Free

Free mentorship
60+ language tracks
Syllabus-based
Open source

AtCoder

Japanese competitive programming platform with high-quality problems.

Competitive

Intermediate-Advanced

Free

Regular contests
Beginner contest
Archive problems
Editorial solutions

Project Euler

Mathematical/programming problems that require more than just code.

Math + CS

Advanced

Free

800+ problems
Math-focused
No time limit
Community forums

TopCoder

The original competitive programming platform with marathon matches.

Competitive

Advanced

Free

Premium

Algorithm contests
Marathon matches
Data science
Paid challenges

CSS Battle

The funnest multiplayer game for CSS. Battle against your friends!

Frontend

All Levels

Free

CSS challenges
Leaderboard
Minimal code wins
Fun format

Frontend Mentor

Improve your front-end skills by building real projects.

Frontend

Beginner-Intermediate

Free

Premium

Real-world projects
Design files provided
Community feedback
Portfolio ready

CodeSignal

Technical assessment platform used by companies for hiring.

Interview Prep

All Levels

Free

Premium

Arcade mode
Interview practice
Company assessments
Skill score

SPOJ

Sphere Online Judge - classical problems from programming contests.

Competitive

Intermediate-Advanced

Free

Classic problems
Multiple judges
Problem clusters
User problems

Practice Tips

1
Start with Easy
Build confidence before tackling medium/hard problems
2
Focus on Patterns
Learn common patterns like sliding window, two pointers, BFS/DFS
3
Time Yourself
Practice under time pressure to simulate real interviews
4
Review Solutions
Always check optimal solutions after solving