Stack Your Cards
Stop leaving money on the table. Maximize every purchase with the right card, the right portal, and the right strategy.
What Is Stack Your Cards?
Stack Your Cards is a free credit card optimization tool that tells you which card to use for every purchase. No account required, no data collected — just smarter spending.
Here's the core insight: if you carry more than one credit card, you're almost certainly leaving hundreds or thousands of dollars on the table every year. Your Amex Gold earns 4x at restaurants. Your CSR earns 3x on travel. Your Freedom Flex earns 5% on rotating categories. But are you always pulling out the right one?
Most tools just compare card rewards. We go further: we stack three independent layers of savings — card rewards + cashback portals + affiliate commissions — and factor in hidden value like rental car insurance and purchase protection.
The Three Layers of Savings
Card Rewards
Every card earns different rewards in different categories. Your Amex Gold earns 4x at restaurants, your CSR earns 3x on travel, your Freedom Flex earns 5% on rotating categories. We tell you which card wins for each purchase.
Cashback Portals
Sites like Rakuten, TopCashback, and Honey give you additional cashback when you shop through their links. This stacks ON TOP of your card rewards. It's a completely separate rebate.
Affiliate Commissions
Many stores offer affiliate programs. If you're signed up, you can earn an additional commission on your own purchases. This is the third independent layer of savings.
📐 Real Example
$500 Nike Purchase — All Three Layers
Without optimization, you might earn just $5 using a flat 1% cashback card. That's an $80 difference on a single purchase.
Feature-by-Feature Guide
Search any merchant, enter your purchase amount, and instantly see which card to use — ranked by total savings including rewards, offers, portal cashback, and affiliate commissions.
Type the merchant name → enter your amount → see every card ranked with total dollar savings. The #1 pick is your best bet.
- 💡Check the portal badges — they show extra cashback you can stack on top
- 💡Look for ⚠️ benefit callouts like rental car insurance or purchase protection
- 💡Toggle "Show all cards" to see how non-wallet cards compare
Pick a spending category and see which card in your wallet earns the highest effective return rate. Perfect for quick lookups when you know the category but not the specific merchant.
Select a category (dining, travel, groceries, etc.) → see cards ranked by effective return percentage.
- 💡Great for categories like "gas" or "groceries" where you shop at multiple stores
- 💡Compare your wallet cards vs. all available cards to spot upgrade opportunities
Enter your monthly spending by category and see annual rewards across all your cards. Identifies total annual value per card, net value after annual fees, and flags "dead" cards costing you money.
Enter your estimated monthly spending for each category → see annual rewards projections and net value after fees.
- 💡If a card shows negative net value, it's costing you more in fees than it earns — consider downgrading or canceling
- 💡Use this to justify keeping (or ditching) premium cards
Based on your spending patterns, discover which new cards would earn you the most incremental value. Shows first-year value (with sign-up bonus) and ongoing annual value.
Enter your spending → see recommended cards ranked by how much more they'd earn you vs. your current setup.
- 💡Factor in the sign-up bonus — it can be worth $500–1,000+ in the first year alone
- 💡Look at the "ongoing value" column to see if the card still makes sense in year 2+
Add the credit cards you carry so all analysis is personalized to your actual wallet. Browse 44+ cards from every major issuer.
Browse cards by issuer → click to add → your wallet persists across sessions using your browser's local storage.
- 💡Add ALL your cards, even the ones you rarely use — you might discover one is optimal for a category you didn't expect
- 💡Your wallet is stored locally — no account needed
Track active promotions like Chase Offers, Amex Offers, and Citi Merchant Offers. These temporary deals can swing which card wins for a specific purchase.
Add your real offers as they appear in your card apps → they automatically factor into Smart Checkout results.
- 💡A $10 Chase Offer at CVS can make your Freedom the best card even if another card has a higher base rate
- 💡Check your card apps weekly — new offers appear all the time
Shows available cashback rates from 9 major portals for each merchant. Portal cashback stacks on top of your card rewards — it's literally free money.
Search a merchant → see cashback rates from Rakuten, TopCashback, PayPal Honey, BeFrugal, Swagbucks, Capital One Shopping, RetailMeNot, Ibotta, and Mr. Rebates.
- 💡Always check before buying online — takes 30 seconds and saves real money
- 💡Some portals offer elevated rates during holidays and sales events
- 💡Portal cashback is a separate rebate — it doesn't reduce your card rewards
Tracks affiliate commission opportunities for self-referral. Shows commission rates, cookie durations, and self-referral policies for major retailers.
Browse merchants → see affiliate programs → sign up for ones that allow self-referral → earn commission on your own purchases.
- 💡⚠️ Check each program's terms — some explicitly prohibit self-referral
- 💡Cookie duration matters: longer cookies mean you have more time between clicking and buying
Comprehensive database of card perks beyond points: rental car insurance, purchase protection, extended warranties, travel insurance, lounge access, cell phone protection, and more.
Browse by benefit type or by card → see which cards offer the best coverage for each category.
- 💡Primary rental car insurance on a CSR saves $30/day — that can outweigh any points differences
- 💡Purchase protection can save you hundreds if something breaks or gets stolen
- 💡These benefits alone can justify a card's annual fee
Tracks your benefit usage throughout the year with progress bars showing annual fee recovery. See benefit-by-benefit usage, expiration warnings, and which credits need attention.
Select a card → log benefit usage as you use them → watch your fee recovery percentage climb.
- 💡🔴 Red = unused benefits expiring soon — use them or lose them
- 💡🟡 Yellow = partially used — you still have value to capture
- 💡🟢 Green = fully used — you're maximizing this benefit
- 💡Check monthly to make sure you're not leaving credits on the table
Quick Start Guide
Go to My Wallet and add your credit cards
My Wallet →Go to Smart Checkout and search for where you're shopping
Smart Checkout →Enter the purchase amount
Use the recommended card + check portal/affiliate badges for extra savings
Log any benefit credits used in the Dashboard
Dashboard →Add your active card offers in Offers as they appear
Offers →Check the Dashboard monthly to make sure you're maximizing annual fee recovery
Add your cards and start saving in under 2 minutes
Frequently Asked Questions
“Is this free?”
Yes, completely free. No ads, no affiliate links (yet). Just a tool built to help you optimize your rewards.
“Do you store my card numbers?”
No. We never ask for actual card numbers. You just select which cards you carry from our database. Everything is stored locally in your browser.
“How accurate are the rewards rates?”
We maintain a database of 44+ major US credit cards with current reward structures. Point valuations are based on industry-standard estimates (similar to The Points Guy). You can even customize valuations in Settings.
“Can I use this on my phone?”
Yes! It's fully responsive. Works great on mobile — perfect for checking at the register before you swipe.
“How do the three layers stack?”
Card rewards are earned directly from your card issuer. Portal cashback is a separate rebate from the portal company. Affiliate commissions are a third separate payment from the retailer. They all stack independently — no conflicts.
“What about rotating categories?”
We track rotating 5% categories for cards like Discover It and Chase Freedom Flex, including which quarter they apply to. Activate those categories in your card apps to take advantage.
The Math Behind It
Not all points are created equal. Here's how we calculate effective return rates — the actual dollar value you get back per dollar spent.
Points × Valuation = Dollar Value
4x Amex MR points × $0.02/pt = 8% effective return
Each rewards currency has a different value. We use industry-standard valuations that factor in transfer partner redemptions, not just statement credits.
Portal Booking Multipliers
CSR 10x on hotels via Chase Travel × 1.5¢/pt = 15% return
Some cards offer elevated earning rates when you book through their travel portal. Combined with higher point valuations, the effective return can be massive.
Transfer Partner Valuations
1 Chase UR → 1 Hyatt point → ~2.0¢ value vs. 1¢ cashback
Transferring points to airline/hotel partners often yields 1.5–2.5× more value than cashing out. That's why transfer partner math matters.
Why Points ≠ Cents
1 Chase UR ≠ 1 Amex MR ≠ 1 cent
Chase UR points are worth ~1.8–2.0¢ via transfer partners. Amex MR points are worth ~1.8–2.0¢. Capital One miles are worth ~1.7¢. Citi ThankYou points ~1.5¢. A flat 2% cashback card earns 2¢ per dollar — but 4x MR earns 8¢.
Ready to stop leaving money on the table?
Add your cards. Search a merchant. See the difference.