The cart is the most expensive place in a store: the user has already decided to buy, and every loss here is nearly-earned revenue walking away. These are the rules we validated on projects, including the grocery marketplace checkout relaunch.
One screen beats five
A multi-step checkout looks “simple per step”, but every transition is an exit point. A single-page flow with progressive field disclosure lifted cart-to-order conversion by 21%. Important: single-page does not mean a wall of 20 fields — fields appear as you fill.
Guest checkout is mandatory
Forced registration causes up to 30% of abandoned carts. Offer an account after payment, when the user has already received value: conversion to sign-up at that moment is several times higher.
Address autocomplete
Predictive input cuts address entry from 40 seconds to 8 and nearly eliminates delivery errors. The integration pays for itself in weeks.
Honest price from the start
Delivery cost appearing at the last step is the classic abandoned-cart cause. Show the full price as early as possible, even when it is not in your favor: rebuilding trust costs more.
Errors next to the field, in human language
“Invalid format” is the worst error text. Say what to fix: “The phone number is one digit short”. Validate as the user types, not on the Pay button.
- Persist the cart across sessions and devices
- Show delivery timing before, not after payment
- Duplicate the pay button on long screens
- Usability-test every checkout release
Want to know where your checkout leaks? Order a UX audit: in our experience the three most expensive problems surface within the first week.