Plans, quotas & billing

You can get a long way for free. This page explains where the lines are and how billing works when you decide to cross them. For the exact numbers and current prices, the Pricing page is always the source of truth — we don't repeat them here so they can never drift out of date.

Free vs Pro, in one paragraph

Free gives you the entire Algorithms track, performance-graded, with time and memory metrics on every test, the guided tour, progressive hints, and the speed leaderboards — no credit card. Pro opens the other four tracks (Database / EF Core, Refactoring, Architecture, and Secure Coding), the full hidden performance suites, every guided path, and removes the daily caps. See the feature matrix for the line-by-line comparison.

What counts against your quota

The one limit you'll actually feel on Free is the daily submission cap, and the distinction between the two run buttons is exactly what keeps you under it:

• Run never touches your submission quota. Executing the sample cases doesn't draw down your daily submissions, so iterate as much as the puzzle needs. The one catch: signed-in Free accounts get a generous daily run ceiling of 50 runs as an abuse guard. Pro and Pro+ lift it entirely.
• Submit counts. Grading against the full hidden suite is what draws down your daily quota.

So the habit from Getting started — Run until the samples pass, think, then Submit — isn't just good practice, it's how you make a day's submissions last. The quota resets every day; nothing carries over and nothing is lost.

Revealing a reference solution is also capped per day on Free (and uncapped on Pro). Revealing never costs you a submission and never marks the puzzle as solved — it's there to study, not to penalize.

Upgrading and downgrading

Upgrading to Pro takes effect immediately — the locked tracks and the full gates open the moment payment clears. Billing is monthly or annual, and annual is the cheaper per-month rate; the Pricing page shows both alongside any running promotion.

If you cancel, you keep Pro until the end of the period you've already paid for, then drop back to Free. Your solved history and in-progress work stay put across the change — downgrading locks tracks, it never deletes anything.

Payments and refunds

Payments are handled by our reseller, Paddle, who act as the merchant of record and issue the receipt for your purchase. Card details never touch our servers.

If a subscription isn't what you expected, see the Refund policy for how refunds are handled, and the Terms of Service for the full agreement. The fastest route to a billing question is always email: [email protected].