Why this list is two tools, and a disclosure
Upsell and cross-sell on Shopify is a narrow, serious category in 2026, and our catalogue has two tools worth ranking: Rebuy and LimeSpot. We are not padding it with generic “boost your AOV” widgets or apps that bolt a single post-purchase offer onto checkout and call it a personalization platform. These two are real recommendation engines, both Built-for-Shopify, both rated 8.9/10 in our catalogue.
One disclosure up front: neither Rebuy nor LimeSpot runs an affiliate program we earn from. That makes this a purely editorial ranking — the order below tracks fit, not commissions, because there are no commissions. Prices verified directly on each vendor’s pricing page (LimeSpot 2026-06-04, Rebuy 2026-05-30).
#1 — Rebuy (the pick for cart and checkout personalization)
Rebuy is the stronger pick when your upsell strategy lives in the cart and at checkout. Its Smart Cart drives measurable AOV lifts through cross-sell and upsell widgets across the cart, checkout extensions, and post-purchase pages, with 35+ integrations and no-code/low-code building blocks. For Shopify and Shopify Plus stores with a diverse catalogue (10+ SKUs), that breadth is the difference between a single static upsell and a personalization layer that adapts per shopper.
Pricing is tiered and climbs quickly: a Build-Your-Plan option from $25/mo, Starter at $99/mo, Grow at $749/mo, and Enterprise at $999/mo+. Two honest caveats: initial widget setup can be complex (this is a platform, not a one-click app), and the Grow tier at $749/mo is steep for small brands. For stores where a few points of AOV lift clears that cost, Rebuy pays back; below that, the price tag outruns the return. See the Rebuy pricing breakdown for the tier math.
#2 — LimeSpot (the pick for AI product recommendations)
LimeSpot (8.9/10) is the choice when AI-driven product recommendations are the actual job — personalized recommendation carousels, cross-sell and upsell blocks across the storefront, set up without a developer. Where Rebuy centres on the cart, LimeSpot spreads personalization across the whole shopping journey (home, collection, product, cart). Support is a repeated strength in reviews, and theme installation on OS 2.0 is genuinely easy.
Pricing is revenue-banded: LimeSpot Max is $150/mo for up to $50,000 in 30-day online-store revenue (a 50% lifetime discount promo for new signups makes that effectively ~$75/mo), with higher revenue bands costing more. The honest caveat: because pricing is tied to store revenue, it escalates as you grow, and a couple of reviews flag attribution questions (draft products surfacing in recommendations). For a brand that wants storefront-wide AI personalization without engineering time, it earns the second slot. The LimeSpot pricing breakdown covers the revenue bands.
The honest verdict
Pick Rebuy when your AOV lever is the cart and checkout — Smart Cart, post-purchase offers, and deep cart personalization are its core, and the integration breadth suits a complex catalogue. Pick LimeSpot when storefront-wide AI product recommendations are the job and you want them live without a developer, accepting that revenue-banded pricing climbs as you scale.
We do not list a third upsell app, because the catalogue does not have a third we would put in front of an operator in mid-2026 — and we tell you plainly that neither of these two pays us, so the ranking is fit and nothing else. If your real need is broader merchandising, the Rebuy vs cart-personalization and recommendation comparisons are the next read; for pure post-purchase retention, returns and subscriptions are different jobs covered elsewhere on the site.