Scalpel Stack vs Wappalyzer
Both name the tech behind a site. Wappalyzer has the bigger dataset and a commercial platform; Scalpel Stack sends nothing and requests no host access.
Wappalyzer is made by Wappalyzer. Facts checked against public sources on 19 July 2026, and linked at the end. Where a source is silent, the table says "Not documented".
Wappalyzer is the best-known technology profiler. It detects content management systems, ecommerce platforms, web servers, JavaScript frameworks, and analytics, and it's the front end of a large commercial dataset that Wappalyzer sells as lead lists and APIs.
Scalpel Stack does the same core job, locally, against a bundled snapshot of the open webappanalyzer fingerprint database, and it shows the evidence behind every detection. The interesting difference is what each one does with the sites you visit. The facts below come from Wappalyzer's own privacy policy and store listing.
Feature by feature
| Feature | Scalpel Stack | Wappalyzer |
|---|---|---|
| Detects CMS, frameworks, analytics, servers | Yes, across nine on-page signals. | Yes, its core feature. |
| Fingerprint database | A version-pinned snapshot of the open webappanalyzer database, bundled in the extension. | Wappalyzer's own dataset, maintained as a commercial product. |
| Evidence trail | Every detection shows the vector, the pattern, and the matched text you can verify. | Not documented; the extension lists detected technologies. |
| Version and confidence | Versions from fingerprint capture groups, plus a 0 to 100 confidence score. | Version detection yes; a surfaced confidence score is not documented. |
| When it reads the page | Only when you click the icon (activeTab). It requests no host permissions. | Analyses sites as you browse. |
| Server-side detection | Optional one-click header check that fetches the current tab's own URL. | Yes, part of its detection. |
| Exports | Free JSON, Markdown, and CSV. | Bulk data, lists, and lookups are paid Wappalyzer plans; free in-extension export not documented. |
What happens to your data
The part that's easy to miss. This is where the two tools differ most, and every claim here is drawn from the sources below.
| Feature | Scalpel Stack | Wappalyzer |
|---|---|---|
| Where detection runs | Entirely in your browser, against the bundled database. | In your browser; the extension works without an account. |
| Sends site data to the vendor | Never. It makes no requests of its own. | When sharing is enabled, it "periodically sends limited website-level data" (hostname, HTTP or HTTPS, detected technologies, and metadata) to Wappalyzer. |
| Full URLs or page content | Never sent. | Per its policy, requests "do not include full page content or full visited URLs". |
| Data sold | Nothing leaves your machine, so there's nothing to sell. | Collected data "may be shared or sold as part of our commercial products and services". |
| Turning sharing off | Not applicable; nothing is shared. | Sharing can be disabled in the extension settings. |
Which should you choose?
Pick Scalpel Stack if
You want technology detection that never leaves your machine, no host permissions, an evidence trail you can check, and free exports.
Pick Wappalyzer if
You want the broadest, most-maintained dataset and the surrounding commercial platform, and you're comfortable with the optional data sharing (or you switch it off).
Our take
Wappalyzer is a serious tool and its dataset is hard to beat. To be fair to it: the data sharing is optional, you can turn it off, and it excludes full URLs and page content. But the default posture of a commercial data company is different from a tool that has no server to send anything to.
Scalpel Stack is the pick when "local only" is the point. It reads the page just when you ask, keeps activeTab-only permissions, and shows you why each technology was detected. You trade dataset breadth for a tool that can't phone home because it never makes a request.