Pricing

Everyone starts free. Verify your email and you get 10 credits, which is enough to work through a real problem set and decide whether the explanations are worth paying for. No card is required to start.

Current plans, prices and credit allowances are shown above.

How credits work

One credit is one substantive request to the AI. That is the whole rule.

Costs a credit

• Solving a problem
• Asking a follow-up question
• Submitting an attempt to Check My Work
• Asking for a different method or another explanation
• Requesting a concept lesson in Learn mode

Costs nothing

• Reading an answer you already generated
• Reopening a conversation from your history
• Revealing a practice hint or answer
• Copying or printing a solution
• Deleting a conversation
• Using any of the AP Physics score calculators

A request that fails on our side is not charged. Credits are held against a request and only settled once the AI actually returns something. If a provider times out or errors, the hold is released. You are also protected against accidental double submission, because the ledger keys each charge to a single request.

Unused credits accumulate rather than expiring at the end of a billing period.

Working out what you need

A credit is a message, not a problem, so the honest way to estimate is by how you study rather than by counting homework questions.

Occasional use. You check a few answers a week and get stuck properly once or twice. The free allowance will last you a while, and the monthly plan is comfortable after that.

A full problem set, worked properly. Ten questions taken one at a time, with a couple of follow-ups on the ones that were genuinely confusing, runs somewhere around fifteen to twenty-five credits. Weekly problem sets across a semester therefore sit well inside a monthly plan.

Tutor mode. Guided sessions use more, because each exchange is its own request. A long tutoring conversation on one hard problem can use ten credits by itself. It is also the version most likely to actually improve your marks, so this is not wasted spend, but it is worth knowing before you use your free 10 on a single conversation.

Exam revision. Heavy periods look different from term-time. If you are working through past papers for a fortnight before an exam, expect several times your normal usage in those two weeks. The annual plan exists mostly for this pattern, since credits carry over and revision is bursty.

If you are unsure, start monthly. Nothing is locked in.

Billing

Payment is handled by Stripe. Card details are entered on Stripe’s own hosted checkout page and never touch this site or our servers.

When a payment succeeds, the credits for that billing period are added to your account automatically. On the monthly plan that happens every month; on the annual plan the full allowance is granted when the invoice is paid.

Manage everything from the Billing button on your account page, which opens Stripe’s customer portal. From there you can update your card, change plan, view invoices and cancel. Cancelling stops future billing and leaves your access in place until the end of the period you have already paid for. Credits already in your balance remain yours.

Refund terms are on the refund and cancellation policy page.

What you get on any plan

Plans change how many credits you have, not what the product does. There is no feature paywall between the free tier and a subscription:

• All four modes: Solve, Learn, Tutor and Check My Work
• Image and PDF upload
• Full structured answers with assumptions, equations, worked steps and independent arithmetic checks
• Validated interactive Physics visuals with controls, live readouts and Play/Pause animation where supported
• Copy notes and Print / Save PDF actions for complete answers
• Conversation history and follow-ups
• The Physics AI Tutor and homework help entry points

The AP Physics score calculators are free for everyone and never use credits, whether or not you have an account.

Common questions

Do I need a card to start? No. Register, verify your email, and the free credits are added.

Why do I have to verify my email? Free credits are granted after verification. It is the simplest way to prevent one person opening unlimited free accounts, and it means your conversation history persists.

Does a failed request cost me a credit? No. If the AI does not return an answer, the credit is released.

Do unused credits expire? No. They accumulate.

Can I buy credits without a subscription? Not currently. The available options are the free allowance and the recurring plans shown above.

Can I cancel anytime? Yes, from the Billing button on your account page. You keep access until the end of the period you have paid for.

What happens to my credits if I cancel? Credits already granted stay in your balance. You simply stop receiving new ones.

What happens if a payment fails? Your subscription status updates from Stripe automatically. Existing credits are unaffected; you just do not receive the next allowance until billing succeeds.

Is there a student discount? The plans are priced for students already. There is no separate discount tier.

Do you store my card details? No. Stripe handles payment and is the system of record. We store only the link between your account and your Stripe customer record.

Is this cheaper than a homework answer subscription? Compare on what you actually get. Answer libraries return solutions other students uploaded, and only if your exact question is already there. This generates a worked solution for your specific problem and will discuss it with you. The free 10 credits exist so you can judge that for yourself before paying.

What if the AI gets something wrong? Every answer has a thumbs down and a Report button, and reports reach us. What is checked automatically and what you still need to verify yourself is set out on the accuracy and method page.