About CardLab
CardLab is a private credit card tracker that ranks your cards for each purchase and tracks bank bonuses against each bank's own deposit rule, for people who manage their own cards and bonuses without linking a bank.
What CardLab does
CardLab keeps statement dates, due dates, utilization and reward caps for the cards you enter by hand, in one calendar, on the credit card tracker. Best Card ranks the cards you hold for a purchase, using rates read from issuer pages, and shows the arithmetic behind the answer instead of just a winner. The bank bonus tracker follows a checking or savings sign-up bonus against the bank's own deposit rule: deposits so far, days left in the window, when the bank pays, and the first day you can close without losing it. The lab and the calculators show what a carried balance costs, how long a payoff takes, and when interest cancels out rewards. CardLab runs on iPhone, and the same maths runs in your browser.
What makes CardLab different
- No bank login. There is no bank connection, no real card number and no CVV. You enter your own cards, and by default everything stays on your device. Optional iCloud sync keeps data in your own private iCloud, and CardLab operates no database of user data.
- Every rate names its source. CardLab reads rates from the issuer's own product page and keeps three things with every number: the page it came from, the exact sentence on that page and the day it was read. A figure that cannot be tied to a sentence is rejected by the build, so it never reaches the app. See how rates are verified.
- Nothing is ranked for money. CardLab takes no commission from any issuer, and no card is ranked, featured or shown higher because of a payment. The app is funded by what people pay for it.
- Modeled exactly, not hand-waved. A decimal-based engine models average daily balance, grace periods and minimum-payment rules, and an automated test suite checks it. CardLab shows an educational Credit Health Meter, never a credit score.
- Built for more than one country. The tracker and simulators work in all 41 country presets and 34 languages. The verified card catalog covers a shorter, named list of markets.
Who uses CardLab
- People with several rewards cards who want to know which card to use for a purchase, and when a bonus cap runs out.
- People chasing checking and savings sign-up bonuses who need the deposit rule, the window and the early-close date in one place.
- People carrying a balance who want to see what it costs this cycle and how long a payoff will take.
- Anyone learning how statements, grace periods and utilization work, on practice numbers before real money is involved.
Who makes CardLab
CardLab is made by a small independent developer and funded by what people pay for the app. It is listed on the App Store as "CardLab: Track Cards & Rewards". Several unrelated products share the name: this CardLab is not CardLab ASA or cardlab.com, which manufacture card hardware, and it is not Stratos or cardlabcards. Questions and feedback go to support@getcardlab.app, or see support.
The data behind CardLab
For the numbers behind bank bonuses, read bank bonus statistics, built from offers read on each bank's official page. For card rewards, read credit card rewards statistics, built from CFPB and Federal Reserve data.