01 · Before
Three cards. One register.
No clue which earns the most on this run.
Grocery run · ~$120 · 3 cards in your wallet, 3 different rates.
CardMax · pick the right card to swipe
Pick the bestcard to swipe.
CardMax is a credit-card optimizer for iOS. Take a photo of what you're about to buy, and CardMax identifies the merchant and category, then ranks every card in your wallet by effective return for that purchase.
TestFlight beta · iOSCap-aware ranking · math in the open
Merchant rules CardMax knows
- Whole FoodsMCC 5411 · Groceries
- ShellMCC 5541 · Gas
- United AirlinesMCC 3000 · Travel
- Olive GardenMCC 5812 · Dining
Best card for this swipe
Rewards · Generic Network
GOLD
4× groceries12.0%
GOLD
12.0% back
4× rate · 3¢/pt · +$14.40 on $120.00
4× on groceries at this merchant (MCC 5411). The runner-up's quarterly grocery cap is nearly full — using it now risks dropping to 1× for the rest of the quarter.
Cap-aware alert87% used
PLATINUM · Q1 grocery cap — keep it for the next quarter, not this run.
Merchant
Whole Foods
Category
Groceries
MCC
5411
Source
merchant rule
Alternatives
PLATINUM · 3× · 9.0%
See it in motion · 3 beats
CardMax in 10 seconds.
Three cards, one register, and a quiet little camera that turns “which one?” into the math.
02 · Snap
CardMax reads the cart.
Merchant, category, cap state — all in one tap.
Merchant detected · MCC 5411
Whole Foods · Groceries
- 12.0%
GOLD best card
4× on groceries
- 9.0%
PLATINUM
3× on groceries
⚠ 87% of Q1 cap used
- 1.0%
BLUE
1× on everything
The math · GOLD
$120 × 4× × 3¢/pt = $14.40 back(vs. $1.20 at 1× = +$13.20)
03 · After
Swipe the right card.
Pocket the math. Wallet stays informed.
Best for this swipe
GOLD
4× groceries12.0%
+$13.20 vs default 1× card
Wallet updated · logged to Recent
Cap-aware ranking · math in the open · merchant rules baked in
TestFlight beta · iOSTestFlight beta
Get a TestFlight invite for CardMax.
One email when we ship. Nothing else.
What it does
The receipt math you weren't doing.
Snap before you swipe
Photograph the cart, storefront, or receipt — CardMax recognizes the merchant.
Optimal pick, with the math
Every card in your wallet ranked by effective return for this exact purchase.
Cap-aware
Knows your $1.5K Q1 grocery cap and stops recommending Sapphire when you've maxed out.
CardMax is in TestFlight.
Questions, bugs, or beta invites — reach the dev directly at dapsdev.support@gmail.com.