Start free. Pay once you are hooked.

Every task, free to try, no account needed. Instant checking, hints and the expected result. 3 reference solutions a day with a free account. Progress saved in this browser.

Every reference solution with its explanation, no daily limit. Timed mode with best times. Completion certificates with a verification link. Progress and best times saved to your account, on every device.

Yes. The annual plan starts with a 7-day free trial: nothing is charged today, the card on file is charged $59 on day 8, and cancelling before that from the account page costs nothing. One trial per account.

Yes, in one click from your account page. You keep Pro until the end of the period you paid for and are not charged again.

Yes. Full refund within 14 days of paying, for any reason, from the account page or by email.

Yes. Sign up with a .edu or .ac email and the annual plan is half price automatically.

One payment of $99 for Pro for as long as the site exists, available until 31 December 2026. After that the lifetime price is $149.

Yes. The Dravari bundle gives Pro on every drill site (Excel formulas, shortcuts, Google Sheets, SQL, Python, financial modeling, accounting, statistics and more) for $99 a year, or $199 once (founding price until 31 December 2026).

Yes. The price shown is the price paid; any VAT or sales tax is included.