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 an AI credit card optimizer for iOS — the fastest way to figure out the best card to swipe before you pay. Snap a photo of the storefront, your cart, or the receipt and CardMax identifies the merchant and MCC, ranks every card in your wallet by effective return for that exact purchase, and factors in bonus categories, quarterly 5% rotations, transfer-partner sweet spots, and your Chase 5/24 status. Think of it as a credit card rewards calculator and AI receipt scanner that lives in your pocket — no statement import, no card-number entry, just the math behind which card to pull out.
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.
How it works · 4 beats
Snap, scan, match, swipe.
Use CardMax to pick the best card to swipe in four steps: snap a photo, let CardMax scan the merchant, match against your wallet, and swipe the winner.
- Step 1
Snap
Open CardMax at the register and snap a photo of the storefront, your cart, or the printed receipt. One tap; no menu diving.
- Step 2
Scan
CardMax runs the photo through its vision model and identifies the merchant plus its MCC — “Whole Foods · Grocery · MCC 5411”.
- Step 3
Match
Every card in your wallet is ranked by the effective return for that purchase — multiplier, cents-per-point value, and remaining bonus-category cap all factored in.
- Step 4
Swipe
Pull out the card at the top of the list — CardMax shows the exact effective % back you’re earning and warns when you’re close to a quarterly cap.
FAQ · 8 questions
CardMax, answered.
CardMax identifies the merchant and the merchant category code (MCC) from a single photo, then ranks every card in your wallet by the effective return that purchase would earn — multiplier × cents-per-point — net of bonus-category caps. The card at the top of the list is the one to pull out.
CardMax is in TestFlight.
Questions, bugs, or beta invites — reach the dev directly at dapsdev.support@gmail.com.