Web app · Finance
Cartwise
The price book that answers “is this actually a good price?” in the aisle
Log what you pay — item, store, package size, total — and Cartwise normalises it to $/oz, $/100g, $/fl oz, $/100mL or $/each, then tells you straight up whether this beats the lowest you've ever seen. Free, works offline, nothing leaves your browser.
Stored in your browser only. Nothing you do in the web version is sent to our servers. Clear your browser data and it's gone — so export a backup from the in-app menu if you want to keep it.
In your browser
What you can do in Cartwise on the web
Unit price, worked out for you
A giant box against a small one in one glance. Type the size in oz, lb, g, kg, fl oz, quarts, gallons, mL, litres or a count — Cartwise converts and compares like for like.
The good-deal verdict
Every price is scored against that item's own lowest ever: best price you've seen, good, a little over your low, or over your low — with the exact percentage.
Live verdict while you type
The quick-log screen shows the unit price and the verdict before you save, so you can decide at the shelf rather than at the till.
Cheapest-first store comparison
Per item, one row per store keeping that store's best price, crowned winner first, with how far above your low each of the others sits.
Best-price wins across your whole book
A leaderboard of which store is cheapest on the most items, what the others cost you on average, and your basket priced at your best stores versus your worst.
Price history and stock-up flags
A line chart of every logged price for an item, plus Stock up / Worth watching / Wait lists driven by how close today's price sits to your record low.
Your book, exportable
Download the whole price book as CSV with every normalised unit price, or a JSON backup — everything included, nothing locked.
Screens
Every screen, rebuilt for the browser
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1
Price book
Basket savings, what's at your low right now, and every item with its lowest price and best store.
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2
Item detail
The shelf tag verdict, price history chart against your low, cheapest stores and every price ever logged.
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3
Log a price
Item, store, size in any compatible unit and total — with a live unit price and verdict as you type.
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4
Stores
Which store wins on the most items, what the others cost you, and the biggest spreads in your book.
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5
Deals
Stock up now, worth watching and wait — plus your basket priced at your best and worst stores.
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6
Settings
Default measure, price-book order, the unit table Cartwise normalises, CSV export, sample data and erase.
Try it with sample data: Loads a twelve-item price book — peanut butter, olive oil, eggs, yogurt, coffee, chicken, oats, milk, cheese, paper towels, beans and bananas — priced across Aldi, Kroger, Walmart, Costco and Trader Joe's over the last six weeks. You can start fresh at any time.
Ready? It's free.
Sign in once and every All Things AI web app opens instantly. No install, no subscription, no data leaving your browser.
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Questions
Is the web version of Cartwise free?+
Yes. Sign in with a free All Things AI account and use every screen — no subscription, no in-app purchases.
Where is my data stored?+
Only in this browser's local storage. Nothing you enter is sent to our servers, so we can't see it, back it up, or restore it. Clearing site data, a private window, or another device starts empty. Export a backup from the in-app menu to keep it.
Do I need an account?+
You can read about the app without one, but you must sign in to open it. Sign-in is free and takes a few seconds with Google.
How is the web version different from the Cartwise iPhone app?+
No barcode scanning on the web — you type the digits under the barcode once and search finds the item by code after that. Stock-up flags appear when you open Cartwise rather than arriving as a push notification like on the iPhone. Your price book lives in this browser only, so it won't follow you to another device unless you export a backup and load it there.