Practice without limits
OpticBench Premium
The SEO surface of this site is the free product: every calculator, guide, and reference page, forever. Premium is for heavy practice: the timer, the volume, and the analytics.
What Premium adds
- Timed exam mode with a configurable question count and clock
- Unlimited drills every day (free tier: 10 per day per skill)
- Progress analytics: per-skill accuracy, streaks, and history
- Downloadable printable formula sheet
Weekly, yearly and lifetime plans are available.
Free forever
- Every calculator
- Every guide and reference page
- Untimed drills (10 per day per skill)
- The on-screen formula sheet
Choose a plan
Good to know
Questions
What stays free?
Every calculator, every guide, every reference page, the on-screen formula sheet, and untimed drills at 10 per day per skill. No account is needed and nothing you enter leaves your browser.
What does Premium add?
The heavy-practice conveniences: timed exam mode with a configurable question count and clock, drills with no daily cap, per-skill accuracy, streaks and history, and a downloadable printable formula sheet.
Are the answers different in Premium?
No. Every formula, every worked step and every generated problem is identical for everyone. Premium removes a volume cap and adds the timer and the analytics; it hides no figure and changes no calculation.
How is my access stored?
Purchases are handled by RevenueCat and Stripe. An anonymous purchase id is kept in this browser so OpticBench recognises your Premium on this device. Keep your receipt email for recovery.
I already subscribed on another browser or device - how do I get Premium here?
Head to Restore access and paste the access code shown on this Premium page, or the one from your receipt. Premium moves to this browser instantly.
Can I cancel?
Yes. Subscriptions renew automatically and can be cancelled anytime from the link in your receipt email. Lifetime is a one-time payment.
Lost your access code?
Your code is shown on this page whenever you are subscribed here, and it is in your purchase receipt email. If you cannot find it, reply to your receipt email from the address you paid with - your subscription is tied to it and access can be recovered from there.