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CLUSTER PROGRAMMING-CHALLENGES-CODING-2 · 21 ENTRIES · EARLIEST ENTRY 2025-11-01

Competitive coding judge platforms

This cluster consists of web platforms for solving programming challenges with automated judging, including competitive features like contests, duels, and ratings. Dated entries appear in Dec 2024, Nov 2025, and May 2026 with 1, 2, and 2 members respectively, a sparse pattern with no clear growth trend. OJ_Insight leads on traction with 59 stars, while CampusCode has 2 and another member has 1.

Entry timeline

ENTRY TIMELINE

DEC 2024: 1NOV 2025: 3MAY 2026: 2AUG 2026: 6SEP 2026: 4OCT 2026: 5
DEC 2024OCT 2026

Each bar is the month a member carries, which is a creation date where the source published one and a crawl date otherwise. Nothing in the index was found before 11 August 2026, and coverage broadened sharply on 14–15 August, so a bar from then on reports how much we found that month, not how much was built; an earlier bar reports how far back a member's own source dated it — not how long we have been watching.

Members by activity

Activity signals, not revenue.

Build origin · 2 ai-built · 4 hand-coded · 14 unlabelled

Operator · 11 hobby · 1 open source · 8 unlabelled

Two labels per entry, never collapsed into one: how it was built, and who stands behind it. Counted over the 20 listed below. Unlabelled means nothing has decided yet — not that the answer is small.

  1. 01OJ_Insight59★24 days—hobbyDesktop dashboard that aggregates and visualizes competitive programming statistics and activity across multiple online judge platforms.
  2. 02porch3★3 dayslivehand-codedhobbyA web app for practicing competitive programming problems with friends, featuring authorization, practice sessions, leaderboards, and progress tracking.
  3. 03CodeJudge0★3 daysliveSandboxed online judge platform for running real-time programming contests and securely evaluating student code submissions.
  4. 04CampusCode2★29 days—A full-stack coding practice platform with live code judging and role-based dashboards.
  5. 05BeastCode0★5 days—hobbyWeb platform for competitive programming where users solve coding challenges and receive automated judging.
  6. 06ninjathons0★10 days—hobbyCompetitive coding platform where users practice coding, compete in live 1v1 and territory matches, and take part in challenges.
  7. 07discord-bot0★today—Discord bot that gamifies competitive programming practice with XP balancing, team challenges, boss battles, and seasonal resets for coding communities.
  8. 08codearena0★14 days—hand-codedhobbyWeb-based online judge for competitive programming with sandboxed code execution, contests, and ratings across a multi-judge problem archive.
  9. 09judgex-frontend0★7 dayslivehobbyOnline judge that lets programmers solve coding challenges, submit solutions, and see verdicts from automated test cases.
  10. 10CP-Arena0★1 mo—Competitive programming platform with Elo-based 1v1 matches, Codeforces integration, and custom lobbies.
  11. 11CodeArena0★1 mo—hand-codedhobbyReal-time 1v1 competitive programming arena where users challenge each other in coding duels, with ratings and leaderboards.
  12. 12codexa0★2 molivehand-codedhobbyOnline coding judge and learning platformthat executes code, evaluates test cases, provides AI feedback, and hosts doubt-resolution forums for students and teachers.
  13. 13AlgoBattle0★1 molivehobbyReal-time competitive coding platform that pairs programmers to solve the same algorithm problem and ranks on an ELO leaderboard.
  14. 14cataben.frontend0★2 mo—Coding practice platform for programmers with a challenge editor, leaderboards, learning paths, achievements, and rewards system.
  15. 15oj_helper0★1 yrabandonedliveopen sourceApp for looking up information about online judge platforms used for programming competitions.
  16. 16nLogn1★5 mo—Competitive programming platform for practicing algorithms and participating in contests.
  17. 17Pixel-Judge1★10 mostalelivehobbyOnline judging platform that lets users submit programming solutions to coding challenges and receive automated correctness feedback.
  18. 18code_duel0★4 moliveai-builtWeb app that lets users engage in coding duels or competitive programming challenges against each other.
  19. 19NUCPC0★11 mostale—hobbyWeb platform that hosts programming contests for university students with authentication, contest management, and automated code evaluation.
  20. 20codebattle0★11 mostale—ai-builtPlatform where users compete against each other by solving programming challenges in real time.

Ranked by traction, highest first, and paged 20 at a time — this is a window on the cluster, never the whole of it. Ties are broken by a stable id so a product cannot appear on two pages or fall between them. Browse every cluster.