Full-stack · queues · workers · reliability

Daily coding challenges

Ship the fix, match the expected output, beat the clock. Scores blend correctness, speed, and code quality across multiple languages.

UTC day2026-06-04
Members only — live puzzle hidden

You’re seeing a preview layout. The real brief, expected output, and starter code for today appear after you sign in. The article below is available to everyone and helps explain the feature to people and search engines.

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PREVIEW

Target: 20 min · Language: nodejs

Brief

Each UTC day, members get a concrete bug-fix or output-matching exercise with real starter code and expected output. Create a free account and sign in to load the live puzzle, run it in our environment, submit once for a scored run, and appear on the leaderboard.

Expected output

The exact expected output for today is shown here after you sign in. This line is only a preview.

Your solution

Sign in or create an account to load today’s real challenge and submit.

What are Codeground Daily Challenges?

Daily Challenges give you one short coding exercise every calendar day (UTC), focused on fixing real bugs, tightening logic, and matching an expected program output—the kind of feedback you get in a code review or PR, not just memorized patterns. Sign in, edit the starter code, run against the same environment style as our main playgrounds, then see your score, how you rank today, and a simple score trend on your profile over time.

How a day works

Each day you get a single challenge with instructions, a target time hint, and the exact output your program should print. Your job is to read carefully, fix or complete the code, and submit when you are happy with the result. Everyone competes on the same puzzle for that UTC day, so the leaderboard compares apples to apples. Challenges are chosen from a large pool so you are unlikely to see the same one twice for a long time.

How your score is built

Your total is out of 100. Most of the points come from correctness—does your output match what we expect, line for line? You also get credit for speed relative to the suggested time window, and for code quality via an automated review so tidy solutions are rewarded. To keep the board fair, each signed-in user gets one scored submission per challenge day—so submit when you are ready.

Languages & extra practice

Puzzles rotate across Node.js, Python, Java, and C++. When you want open-ended practice, use our full online editors (same family of tools as the challenge runner):

Why use Daily Challenges?

They complement heavy algorithm sites: here you spend minutes on precision, language quirks, and small mistakes that break production. That makes them useful for interview prep, onboarding onto a new stack, or a daily warm-up before real project work. The leaderboard and profile history add light motivation without turning every session into a grind.

Frequently asked questions

When does today’s challenge change?

A new challenge is tied to the UTC date. After midnight UTC, you will see the next day’s puzzle and leaderboard (your local clock may still say “yesterday”).

Can I submit twice on the same day?

No. After your first successful submission for that day’s challenge, the run is locked in so everyone plays under the same rules. You can still read the problem and practice locally, but only one score counts for the board.

Do I need an account?

You can read this page and the FAQs without signing in, but the real daily puzzle (instructions, expected output, starter code, leaderboard, and submission) requires a free Codeground account and sign-in. You also need a verified email where we require it to submit.

Is this free? Are there prizes?

Daily Challenges are free to use on Codeground. Bragging rights and your profile graph are the reward today—think habit-building, not cash payouts.

Where do I see my past daily scores?

After you have submitted, visit your public profile from the account menu. You will find a simple history and chart of daily challenge scores over recent days.

What if the site says it cannot load the challenge?

Submissions and the live puzzle need the Codeground API. Check your connection, confirm you are pointed at the right environment, and use Retry on this page. If you only see a static preview, you are in offline practice mode until the backend is available.

How is this different from LeetCode-style sites?

Those platforms lean on big algorithm problems and timed banks. Daily Challenges here stress output correctness, debugging, and language-level gotchas in small programs—closer to day-to-day engineering than to contest math.