BuiltWith vs Wappalyzer: Which Is More Accurate? (2026)

Neither vendor publishes an accuracy figure, so no one can honestly say which is more accurate. Both work the same way. They read the signals a site sends to a visitor, such as HTML, scripts, headers and cookies, and match them to a library of known technologies. What differs is the product around the detection. BuiltWith starts at $295 a month and sells history and lead lists. Wappalyzer has a free tier of 50 lookups a month and paid plans from $250 a month. The table is as at November 2026.

How do BuiltWith and Wappalyzer compare?

The cells below were read on 5 November 2026 from the vendor's own pages. Where a page did not say, the cell says "not published".

Wappalyzer's Pro plan includes 5,000 lookups and Business 20,000. BuiltWith's Basic plan limits you to 2 technologies, 2 keywords and 2 retail reports, and Pro and Team are unlimited. BuiltWith's yearly prices are shown in Australian dollars, so we do not give them. Wappalyzer's pricing page offers 17% off annual billing without listing the annual price.

Which is more accurate, BuiltWith or Wappalyzer?

We cannot say, and neither can the vendors. Neither publishes an accuracy rate or a test set. BuiltWith's own knowledge base says each detection gets a confidence score between 0 and 1, which tells you a detection can be uncertain. Wappalyzer's last open README warns: "Short or generic patterns can cause applications to be identified incorrectly."

The two differ in what they claim to cover. BuiltWith says it tracks "128,218+ internet technologies" and gives usage counts for each. Wappalyzer's pages we read give no count. A larger library is not a more accurate one. It means more things can be named, with more chances to match wrongly.

The way to compare them is to take ten sites whose stack you already know and run both. That is a fair test, and a few minutes of work.

What can each tool detect, and what can neither?

Both read what a visitor's browser receives. Anything the server does not send out is invisible to both of them. The last open Wappalyzer README lists what it matches:

Wappalyzer inspects HTML code, as well as JavaScript variables, response headers and more.

That is from the README of the HTTP Archive fork, read on 5 November 2026.

The same README names several limits. CSS checks are unavailable "when a website enforces a same-origin policy", and only a portion of the CSS rules are used for matching. Those are limits of the open version, which is no longer the product. Wappalyzer's current engine is closed source, so we cannot read its fingerprints.

Server-side software that leaves no tell in headers or markup is out of reach for any fingerprint tool. That includes a database, a back-end language behind a proxy that strips its headers, and an internal service. BuiltWith's pages we read do not say which signals it uses or what it misses, so we make no claim about its blind spots beyond the confidence score. See how to find out what a website is built with for the tells you can read yourself.

Which should you use?

You look up the odd site now and then. Both are free. Wappalyzer gives 50 lookups a month on a free account. BuiltWith says individual lookups are free forever and does not publish a limit.

You need to know when a site changed stack. BuiltWith. It lists 41+ years of technology trends on every plan and has a Change API. Wappalyzer has website alerts, with 5 on the free tier.

You want a list of sites that use a technology. Both sell lead lists. BuiltWith includes them in every plan, Wappalyzer on paid plans only. Check the data rules for your region first, because both sell contact data.

You are building on an API. Compare the pricing page limits. Wappalyzer states credits per plan. BuiltWith lists API products but does not state prices on the page we read.

You are budget-bound. Wappalyzer's Pro plan at $250 a month is $45 below BuiltWith's Basic.

Are there free alternatives to BuiltWith and Wappalyzer?

Yes. You can read the page source, headers and DNS yourself, which the guide to finding out what a website is built with walks through. Or you can use our free technology lookup.

The technology lookup loads a site's homepage once, over HTTPS, with HTTP as a fallback. It matches the HTML, response headers, cookies, script and stylesheet URLs and meta tags against a fingerprint list we maintain, and shows the matches by category: content management and frameworks, servers and hosting, analytics and marketing, security and payments. It also reports the HTTP status and any social profile links. There is no signup and no cost, only a per-visitor rate limit.

It has limits, and its own page states them. It reads one page, once, so anything loaded later by JavaScript, on other pages, or on the server with no tell is invisible to it. Its list covers common technologies and not the long tail. A short result is a limit of detection and not a verdict on the site. It does not hold history, run alerts, or build lead lists. For those, you need one of the paid tools above.

FAQ

Is BuiltWith or Wappalyzer more accurate? Neither vendor publishes an accuracy figure. BuiltWith gives each detection a confidence score from 0 to 1. The only way to know is to test both on sites whose stack you know.

Is Wappalyzer free? There is a free tier. As at November 2026 it includes 50 technology lookups a month, 50 email verifications, 5 website alerts and sample lead lists. The browser extension is listed as a Plus feature.

How much does BuiltWith cost? Basic is $295 a month, Pro $495 and Team $995, as at November 2026. Individual site lookups are free, according to its pricing page.

Is Wappalyzer still open source? No. The README of the HTTP Archive fork says "Wappalyzer is now closed source", and that the browser extension is now closed source as well. The fork is a copy of the last open version, kept for the HTTP Archive monthly crawl.

Can a technology lookup tell what a site's back end runs? Only when the back end leaves a tell, such as a header, a cookie name or an asset path. A server that sends nothing identifying cannot be detected by BuiltWith, Wappalyzer or our own lookup.

What is a free alternative to BuiltWith? Reading page source and headers yourself, or the free technology lookup here. It needs no signup and reads one homepage. It does not keep history or sell lists.