For most of the last decade, the Walmart–Amazon comparison was a parlor game. One was a store company learning the internet; the other was an internet company learning stores. By mid-2025 that frame is stale. Both companies now sell groceries, both run national three-party marketplaces, both operate ad networks measured in the billions, and both are in the prescription drug delivery business. The interesting question is no longer whether they compete — it's where the playbooks diverge, and where, despite the rhetoric, they don't.

The grocery anchor

Walmart's grocery business remains the structural advantage operators we spoke to keep coming back to. A merchandising VP at a regional grocer described it bluntly: "Their basket starts in produce, ours starts in produce, Amazon's basket starts with batteries and a phone charger." Walmart's pickup and delivery business has continued to take share in 2025, and the company has leaned into fresh — expanding automated micro-fulfillment in select stores while keeping the floor-pick model where it still pencils out.

Amazon's grocery answer in 2025 has been more pragmatic than the Whole Foods era suggested. Fresh stores have stopped expanding; the Just Walk Out technology has been pulled from most of them and sold as a B2B product to stadiums and airports. The bet now is on same-day perishables out of existing fulfillment centers, paired with Whole Foods as a premium banner rather than a mass play. A director of category management at a CPG supplier told us Amazon's grocery share gains in 2025 have come almost entirely from the same-day channel, not from physical stores — which matches what their public commentary implies.

Marketplace and the seller squeeze

Both marketplaces tightened the screws on third-party sellers in 2025, but in different directions. Amazon raised effective fees again — a combination of FBA storage, inbound placement charges, and a new low-inventory fee that several aggregators told us is now the single biggest line item after the referral fee. Walmart's marketplace, still smaller, took the opposite tack: lowering commission in select categories to recruit sellers Amazon was bleeding.

The result is a measurable migration we've been hearing about all year. Sellers in apparel, home, and small electrics are increasingly listing on both, with Walmart treated as the second channel they actually invest in rather than the afterthought it was in 2023. None of the operators we spoke to said they were leaving Amazon — the traffic gap is still too large — but the share of marketplace GMV they route through Walmart has climbed into double digits for the first time.

Ads, the actual battleground

If you want to find where Walmart and Amazon are actually colliding in 2025, look at the ad business. Sponsored placements, off-site retargeting via the retailer's data, and connected-TV inventory tied to shopper graphs — both companies are selling effectively the same product to the same CPG buyers, and the buyers know it.

A media director at a top-20 CPG advertiser described 2025 as the first year their retail-media budgets had a real allocation conversation, rather than each retailer being treated as a separate line item. "We're trading off Walmart Connect against Amazon Ads now," they said. "Two years ago we weren't."

Where they don't actually compete

For all the comparison-shopping, there are two areas where the playbooks barely touch:

• Logistics-as-a-service. Amazon's Multi-Channel Fulfillment and its Buy with Prime widget continue to push the AWS-style logic into fulfillment. Walmart's GoLocal effort is real but smaller, and aimed mostly at mid-market shippers rather than competing for the DTC brand persona Amazon is courting.
• Cloud. AWS is, of course, AWS. Walmart's cloud investments are internal. There is no Walmart equivalent — and the company has made clear there isn't going to be one.

What to watch into 2026

The divergence to watch is whether Walmart's automation capex — both DC-side and the in-store pickup automation it has been quietly expanding — drops unit costs enough to widen its grocery price gap into Q1 2026. If it does, Amazon's same-day grocery push gets harder. If it doesn't, the gap closes from the other direction. Either way, the two companies will spend 2026 selling to the same customer with two genuinely different theories of the case. That alone is news.