The major grocery without delivery in the Twin Cities — the fast-growing Aldi chain — is about to add the service.

Aldi last year partnered with Instacart, the San Francisco firm that hires personal shoppers to complete and deliver its customers’ orders, to handle delivery services from stores in a handful of markets. Over the next two months, it will expand the effort to 75 major markets, including the Twin Cities, in 35 states.

“We will start the partnership in some stores in the metro in early to mid-October with nearly full metro suburb coverage by Thanksgiving,” said Matt Lilla, division vice president at Aldi’s Faribault division in Minnesota.

By the end of the year, about 80 percent of Aldi stores will offer online delivery via Instacart. Shoppers can check for local availability.

While every supermarket has felt pressure to offer delivery services, it’s been slow to catch on with consumers. Online grocery sales account for less than 3 percent of the $700 billion spent in U.S. groceries every year. But analysts say that stores without delivery risk being seen as not meeting customers’ needs.

Chicago blogger Mashup Mom tried the service earlier this year. Aldi offered $20 off the first order of $35 and free delivery with a discount code. She found that most items had a slight surcharge compared to in-store pricing, although some prices were identical. A 5-ounce bag of SimplyNature organic spinach was $2.49 in the store and $2.75 delivered.

No items were cheaper on Instacart than in the store. Still, Aldi’s prices were found to be about 40 percent less than the all-store supermarket average in the Twin Cities, according to a recent price comparison by Twin Cities Consumers’ Checkbook, a consumer nonprofit group based in Washington, D.C.

One surprise on the site is the ability to use coupons and coupon codes. Aldi doesn’t accept coupons in-store, but through Instacart, which offers digital coupons for many of its vendors, some national brand coupons may be redeemable if the items are stocked by Aldi online.

Twin Cities Consumers’ Checkbook found that Instacart’s grocery prices can be nearly 20 percent higher than in-store. Fresh Thyme’s prices were 22 percent higher and Costco’s 19 percent, before delivery fees. Overall, Consumers’ Checkbook found that Twin Cities residents who use grocery delivery services such as Instacart, Amazon and CobornsDelivers rate them as “adequate.”

Customers new to Instacart usually get free delivery on the first order of $35 or more. After that, Instacart generally charges about $6 per order, although prices range from $3 to $15 depending on availability and time of day. Consumers placing more than two orders monthly can get unlimited delivery by purchasing Instacart Express for $149 a year, or $15 a month.

Instacart was founded in 2012 and is now in more than 200 U.S. markets. The Twin Cities offers more than a dozen retailers with Instacart delivery service, including Cub, Total Wine, Costco, CVS, Petco, Whole Foods, Lakewinds Co-op, United Noodles, Wedge Co-op, Liquor Boy and Sur La Table. Options depend on your ZIP code.

Aldi, a German discount grocery chain, operates more than 1,800 U.S. stores in 35 states. Unlike most grocery chains, Aldi primarily sells its own brands. The retailer has been expanding aggressively in the United States with plans to spend $5.3 billion to remodel older stores and increase its store count to 2,500 by the end of 2022. Last month, Aldi said it was more than halfway through the planned store makeovers.

In Minnesota, Aldi now has 59 stores, with plans to open stores later this year in the former Rainbow Foods on 26th Avenue S. in Minneapolis as well as in Princeton, Virginia and Marshall. In the first half of next year, Aldi will open in Cloquet, Chaska, Lakeville and Uptown. Additional stores in Chanhassen and two in new locations in St. Paul by the end of 2019 will bring the total to 70 Minnesota stores.