Simple, honest pricing
Start free — no credit card, no trial clock. Upgrade when you want the whole proving ground.
Free
Everything you need to get hooked. No credit card.
- ✓ Full algorithm catalog, performance-graded
- ✓ Time + memory metrics on every test
- ✓ Speed leaderboards
- ✓ Starter learning paths
- ✓ 20 submissions per day
Pro
Most popularFounder pricing — 6 months free · $4.50/mo
The full proving ground: every track, every gate, no daily cap.
- ✓ Everything in Free
- ✓ Database / EF Core track with graded query plans
- ✓ Refactoring katas (Roslyn-measured structure gates)
- ✓ Architecture katas
- ✓ Secure-coding track (adversarial test suites)
- ✓ Full hidden performance suites
- ✓ All guided learning paths
- ✓ Unlimited submissions (fair use)
- ✓ Priority support
Compare every feature side by side ↓
Prices in USD. Taxes calculated at checkout. Cancel anytime.
The feature-by-feature comparison
| Capability | Free | Pro |
|---|---|---|
| Algorithm puzzles (full catalog) | ✓ | ✓ |
| Open practice mode (whole library) | Unlocked tracks only | ✓ |
| Guided learning paths | Starter paths | All paths |
| Submissions per day | 20 | Unlimited (fair use) |
| Time + memory metrics, diff, reveal solution | ✓ | ✓ |
| Speed leaderboards | ✓ | ✓ |
| Database (LINQ / EF Core) track, incl. graded query plans | Preview only | ✓ |
| Refactoring katas | — | ✓ |
| Architecture katas | — | ✓ |
| Secure-coding track | — | ✓ |
| Hidden performance gates | Limited | Full suite |
| System-design challenges * | — | Coming soon |
| Support | Community | Priority |
- * System-design challenges: On the roadmap — Pro will include a monthly minute allowance.
Frequently asked questions
How does payment work? +
Checkout opens inside the app after you sign up — card and local payment methods, with VAT/sales tax calculated automatically and a proper invoice for every charge. Payments are processed by our payment partner, Paddle, so that's the name you'll see on your card statement and receipt.
Can I cancel anytime? +
Yes. Cancel in one click from your account settings. You keep Pro until the end of the period you paid for, then your account falls back to the Free plan — your solved puzzles and progress are never deleted.
What counts as a submission? +
A submission is a graded run against the full hidden test suite (the Submit button). The interactive Run button — sample cases and your own custom inputs — is not counted and is there precisely so you can iterate freely.
What does “unlimited (fair use)” mean? +
No daily cap for humans practicing deliberately. Automated traffic, account sharing, or using the platform as a compute service falls under the Acceptable Use Policy and may be throttled.
Is the Free plan a trial? +
No — it's free forever. You get the full algorithm catalog with grading, metrics, and leaderboards. Pro unlocks the premium tracks (Database/EF, Refactoring, Architecture, Secure Coding), all guided paths, the full hidden performance suites, and removes the daily cap.
What's the founder pricing about? +
We're early, and early members take a bet on us — so annual Pro is currently a year for the price of six months (50% off the monthly rate). The discount applies to the price you sign up at; we'll always announce pricing changes well in advance.
Do you offer team or student discounts? +
Not yet, but we want to. Email [email protected] and tell us about your team or school — early conversations shape what we build.
Try it before you pay for it
The Free plan is the real product, not a demo. See if the grading makes you better — then decide.
Start solving — it's free