Instacart is speeding up grocery delivery. The company announced today it’s debuting a faster delivery service, “Priority Delivery,” in select markets across the U.S. and Canada, with the aim of attracting customers who would have otherwise quickly run to the store for their smaller orders or more urgent demands. At launch, the service will operate in several larger U.S. metros, and will offer deliveries in as fast as 30 minutes, the company says. Instacart is also expanding other speedier delivery services, including 45-minute and 60-minute options, to more cities and retailers in the months to come.

Today, many customers use Instacart to order their larger weekly or monthly grocery orders, but still run to the store when they need a smaller number of items — like ingredients for tonight’s meal, for example. The new Priority Delivery wants to be an alternative to these shorter trips, effectively becoming the grocery delivery alternative to using a store’s express lane checkout.

In the markets where Priority Delivery is live, it will be indicated by supported retailers in the Instacart app with a lightning bolt icon that notes the expected delivery time, like “30 minutes or less.” Customers will also be given the option to choose Priority during checkout, instead of Standard delivery or a scheduled time, if they prefer.

The company tells us there’s not an item limit nor minimum on these types of orders. However, shorter requests — like milk, a few bags of chips and a couple of bottles of wine, for instance — will be fulfilled faster than orders where the customer is requesting specialty deli items, a pickup from a bakery or has a larger basket size.

When the basket size grows larger or the order becomes more complicated, the app will update to display that the 30-minute window is no longer available and display the new delivery time.

Instacart hasn’t yet finalized its pricing for the service, but Priority Delivery will carry an upcharge of some kind. However, the company tells us the fee will be “small” and “incremental,” and will likely be dynamic based on market considerations. It notes that the different delivery options and their associated fees and taxes are displayed during checkout, so there are no surprises.

Initially, Priority Delivery will be available in Chicago, Los Angeles, Miami, San Diego, San Francisco and Seattle, across more than 300 store locations, including grocers and specialty retailers. It plans to roll out the service to more markets and retailers over time.

“We know that no two grocery shops are created equal — whether it’s a bulk buy for the week ahead or just a few ingredients for tonight’s dinner — so we’re launching new features that support the many ways people shop for their groceries today,” noted Daniel Danker, vice president of Product at Instacart, in a statement about the launch. “For many customers, every minute counts when they’re in a pinch and need something in a hurry. With today’s launch of Priority Delivery, we’re redefining the ‘quick run to the store’ and bringing the grocery express lane online for customers,” he added.

In addition, Instacart will expand access to 45-minute and 60-minute delivery options to more cities across the U.S., allowing consumers other options for faster delivery, even if the Priority service is not available.

The move to increase delivery speeds across its footprint could help Instacart better compete with grocery delivery rivals, like Walmart and Amazon’s grocery businesses, as well as Target-owned Shipt.

It also shortly follows Amazon’s announcement last week that it would be shutting down its standalone Prime Now delivery app and website, to instead direct shoppers who want faster delivery on groceries to the Amazon app and website. However, in Amazon’s case, it’s promising two-hour delivery windows on both Amazon Fresh and Whole Foods; not as low as 30 minutes. Meanwhile, Walmart’s membership-based delivery service, Walmart+, doesn’t currently guarantee same-day delivery even for its paying subscribers, as its time slots are on a first-come, first-serve basis. Among the big names, that leaves Shipt — which offers same-day delivery, but not necessarily in 30 minutes.

The update may also make Instacart more competitive with other types of fast delivery businesses which don’t serve grocery retailers — like Gopuff’s “instant needs” delivery service, Uber Eats Essentials or DoorDash, which last year expanded to include convenience store items — including things like chips, ice cream, spices, packaged foods and others that might have otherwise made for a quick store trip.

Instacart’s new service is rolling out now to customers in supported markets.