A feature and pricing snapshot as of October 2026. Vendor pricing changes; confirm current numbers before buying.
| Undercart | BuiltWith | |
|---|---|---|
| Scope | Shopify commerce intelligence | Web-wide technology lookup |
| Domains / stores covered | 1M+ Shopify stores | 491.9M domains |
| Technologies tracked | Shopify apps, pixels, theme app extensions, themes, payments | 127,700 technologies |
| Revenue estimate | Annual + monthly, confidence score, signal breakdown | Spend/revenue data on paid plans |
| Ad library data + creatives | Meta, Google, TikTok | Not a focus |
| Marketing email capture | ✓ | Not a focus |
| Catalog, best sellers, price history | ✓ | Not a focus |
| Traffic rank, trend, top markets | ✓ | Not a focus |
| Free single-site lookup | Free revenue checker; 25 full profiles/mo | ✓ |
| REST API | Every plan | Sold separately (credits) |
| MCP server for agents | Every plan | Hosted MCP (API credits) |
| Chrome extension | ✓ | ✓ |
| Entry paid price | $29/mo (unlimited stores) | $295/mo (Basic: 2 reports) |
| Unlimited plan | $29/mo (unlimited stores) | Pro $495/mo (unlimited reports) |
Sources: Undercart product; builtwith.com/plans and BuiltWith’s API docs, checked October 2026.
BuiltWith answers one question extremely well across the whole internet: what is this site built with? If you sell developer tooling, infrastructure, or anything that maps to a specific technology fingerprint on any platform, its breadth is unmatched, and the free single-site lookup is genuinely useful.
Undercart answers a different question about Shopify merchants: how big is this store, what is it spending on, and is it growing?It pulls the store’s ads and marketing emails, estimates its revenue with a confidence score, shows its best sellers, discounts and product reviews, and tracks its social following and traffic trend. Its app detection is built for Shopify, so it catches apps that generic profilers miss — including ones that run as web pixels or theme app extensions. It will not tell you about a WooCommerce or custom site, where BuiltWith will.
See what Shopify stores actually run in the free Shopify Tech Stacks 2026 report, or check one store’s revenue range with the Shopify revenue checker.
BuiltWith is a web-wide technology profiler: it reports 127,700 technologies tracked across 491.9M domains, on every platform. Undercart is Shopify-only and goes deeper on commerce: the ads a store runs on Meta, Google and TikTok, the marketing emails it sends, a revenue estimate with a confidence score, its best sellers, discounts and product reviews, its social following, and an API/MCP for agents. BuiltWith is broader; Undercart is deeper on Shopify.
BuiltWith is free for individual site lookups — the quickest way to check one site's stack with no account. Lists, exports and reports are paid: Basic is $295/month for 2 technology reports, Pro $495/month for unlimited reports, and Team $995/month for unlimited reports and logins; the API is sold separately.
For Shopify specifically, Undercart is purpose-built: it shows the ads and emails a store runs, estimates revenue (annual first, with a confidence score), shows its best sellers, discounts and product reviews, and detects Shopify apps that generic profilers miss — including ones that run as web pixels or theme app extensions. For non-Shopify or cross-platform technology research, BuiltWith is the stronger choice.
BuiltWith includes website spend and revenue data on its paid plans. Undercart makes revenue a first-class output: an annual and monthly estimate with a confidence score and a “why this number” breakdown on every full profile, plus a free revenue checker that shows any tracked store's range with no account.
Both. BuiltWith sells its API separately from the web plans, priced in credits, and offers a hosted MCP endpoint that uses those credits. Undercart's REST API and hosted MCP server work on every plan, including the free one (25 stores a month); $29/month covers 100 stores and $99/month is unlimited.
Get 25 free store lookups with revenue, ads, email and catalog signals BuiltWith doesn’t focus on.