Stores count on you not doing the division. GroceryGap does it: live prices where a store actually publishes them, your own shelf numbers where it doesn't, and the per-unit math that shows which cart wins — without a single invented price.
Free comparison
The lookup above pulls live prices from stores that publish an API. The box below is for your paper: paste a receipt or your staples list and get the line-by-line read — unit prices, the store-brand swaps, and what a year of the gap costs.
Live lookup — published store APIs
Why this exists
No store is cheapest at everything, and only some publish prices at all. The honest comparison uses live data where it exists, your shelf numbers where it doesn't, and division everywhere — because a 154oz jug at $17.99 and a 150oz at $11.99 is not a $6 question, it's a per-ounce question.
How it works
ZIP + item. Stores with a published API answer live; stores without one get a type-what-you-see cell, clearly labeled.
Receipt or staples list — every line gets a unit price, every gap gets a yearly cost, every store-brand twin gets named as a question to check.
On a paid plan: your tracked staples list, the cheap-cart sheet by store, and re-runs any week.
Plans
Buyer: weekly shoppers watching the bill — families, retirees, anyone feeding four on one income. Channel: frugal-living FB groups, r/Frugal, Nextdoor — español for FL familias.
Your staples, tracked. Re-run the cart any week and see what moved.
Same thing, two months free, one decision.
For food banks, churches and community groups teaching grocery budgeting.
All prices in USD, handled by Stripe. GroceryGap shows live prices only from stores that publish them, takes shelf prices only from what you type, and never invents a number. No store pays for placement.