Find Companies Using jQuery CDN (code.jquery.com) via API

jQuery CDN is the jQuery project's own delivery network at code.jquery.com. When a page loads jQuery from it, the HTML carries a script tag that names the host outright, which makes “uses jQuery CDN” one of the cleanest technographic signals you can read from a public page. It is also a more specific signal than “uses jQuery”: it tells you the team chose to pull the library live from a third party rather than bundle it, and it usually tells you the exact version they pinned.

This guide covers what the code.jquery.com fingerprint is, how it differs from self-hosted jQuery and the other public CDNs, and how to turn a raw domain list into a jQuery-CDN-confirmed lead list with the DetectZeStack API. Every response below is taken from a live scan you can reproduce with the commands shown.

What jQuery CDN Is and Why It Leaves a Detectable Footprint

The jQuery team publishes every release on code.jquery.com, and its download page recommends the CDN script tag as the default way to include the library. A site that follows that advice ends up with a line like this in its HTML:

<script src="https://code.jquery.com/jquery-4.0.0.min.js"></script>

That single tag is the whole footprint. It is not a DNS record, not a response header, and not a TLS certificate, because jQuery CDN never sits in front of the site. It only serves one file the page asks for. Detection therefore happens by reading the fetched HTML body, the same way jsDelivr, cdnjs, and Google Hosted Libraries are detected.

The code.jquery.com script-src fingerprint

DetectZeStack matches the code.jquery.com/ host in any script source and reports a technology named jQuery CDN under the CDN category. The fingerprint also implies jQuery, so a second entry named jQuery appears under JavaScript libraries. When the filename carries a version, as in jquery-4.0.0.min.js, that version is parsed onto the jQuery entry. The jQuery CDN entry itself never carries a version, because a delivery network is not a versioned library.

jQuery CDN vs self-hosted jQuery vs the other public CDNs

The same jQuery file can arrive from five different hosts, and DetectZeStack names each host separately: jQuery CDN (code.jquery.com), Google Hosted Libraries (ajax.googleapis.com), cdnjs (cdnjs.cloudflare.com), jsDelivr (cdn.jsdelivr.net), and Unpkg (unpkg.com). The library entry is the constant; the CDN entry is the variable. That distinction matters for list building. If your segment is “companies that load jQuery from the jQuery project's own CDN,” filter on the jQuery CDN entry. If your segment is “companies that run jQuery at all,” filter on the jQuery entry and ignore the delivery host, as covered in how to detect jQuery on any website.

The self-hosted case is the one that trips people up. WordPress ships its own copy of jQuery under /wp-includes/js/jquery/, so a stock WordPress site returns jQuery with no CDN entry at all. A missing jQuery CDN detection does not mean a site avoids jQuery. It means the site does not fetch jQuery from code.jquery.com.

Why Find Companies Using jQuery CDN

Sales and technographic prospecting signals

A confirmed jQuery CDN reference is a small window into how a team builds. Three things it tends to correlate with:

• Template-driven and agency-built sites. The copy-paste script tag is the path of least resistance for hand-written HTML, themes, and agency deliverables. Teams running a bundler rarely reference code.jquery.com because the bundler inlines the dependency.
• Pinned, visible versions. The version sits in the URL, so you know whether a prospect is on jQuery 4.x, 3.x, or a 1.x release that predates 2016. Pair it with jQuery Migrate and you have a reliable legacy-front-end segment.
• Leaner ops posture. Loading a live third-party script instead of vendoring it is a deliberate trade of control for convenience. That is a qualifier for front-end tooling, performance, and modernization services.

Security and supply-chain review

Every live external script is part of a site's dependency surface. A script tag pointing at code.jquery.com without an integrity attribute means the page trusts the CDN's copy unconditionally, and a pinned old version means known-vulnerable code is served on every page load. Security teams use the CDN category to enumerate exactly which external hosts a domain executes code from, which feeds subresource-integrity audits and third-party-risk reviews. The jQuery entry's cpe field links the detected version to the NVD identifier for jQuery, which is covered in detecting vulnerable technologies with CPE.

How to Detect jQuery CDN on a Single Domain

Manual check: view-source or a one-line grep

Because the fingerprint is a literal host name in the HTML, you can confirm it without any tooling:

$ curl -sL https://jquery.com | grep -o 'code\.jquery\.com/[^"]*' | head -3
code.jquery.com/jquery-4.0.0.min.js

In browser DevTools, the Network tab filtered on code.jquery.com shows the same thing, plus any jQuery UI or plugin files loaded from the same host.

Why manual checks do not scale

The grep works for one domain. It does not follow redirects to the canonical host reliably, it misses tag-manager and lazy-loaded injections that never appear in the initial HTML, and it tells you nothing about the rest of the stack. Across a prospect list you also want the co-detected WordPress, Bootstrap, or Migrate entries, the HTTP status so you can separate blocked scans from real negatives, and a machine-readable shape you can filter. That is the job of the API.

API Example: Confirming jQuery CDN With /analyze

Start with the public demo endpoint, which needs no API key and is rate-limited per IP to 20 requests per hour. The jQuery project's own site is a convenient live example, because it loads jQuery from its own CDN:

$ curl -s "https://detectzestack.com/demo?url=jquery.com" \
  | jq '.technologies[] | select(.name == "jQuery CDN" or .name == "jQuery")'
{
  "name": "jQuery",
  "categories": ["JavaScript libraries"],
  "confidence": 100,
  "description": "jQuery is a JavaScript library which is a free, open-source software designed to simplify HTML DOM tree traversal and manipulation, as well as event handling, CSS animation, and Ajax.",
  "website": "https://jquery.com",
  "icon": "jQuery.svg",
  "source": "http",
  "version": "4.0.0",
  "cpe": "cpe:2.3:a:jquery:jquery:*:*:*:*:*:*:*:*"
}
{
  "name": "jQuery CDN",
  "categories": ["CDN"],
  "confidence": 100,
  "description": "jQuery CDN is a way to include jQuery in your website without actually downloading and keeping it your website's folder.",
  "website": "https://code.jquery.com/",
  "icon": "jQuery.svg",
  "source": "http",
  "version": "",
  "cpe": ""
}

Two entries from one script tag. The jQuery entry carries the version parsed from jquery-4.0.0.min.js and a CPE identifier; the jQuery CDN entry carries neither, because it describes the host rather than the library. Both are source: "http" because the evidence came from the HTTP response body, and both are confidence 100 because a literal host match leaves no ambiguity.

With your API key, /analyze returns the full stack for the domain. Here is the complete response for jquery.com, trimmed only in the description fields:

$ curl -s "https://detectzestack.p.rapidapi.com/analyze?url=jquery.com" \
  -H "X-RapidAPI-Key: YOUR_KEY" \
  -H "X-RapidAPI-Host: detectzestack.p.rapidapi.com"
{
  "url": "https://jquery.com",
  "domain": "jquery.com",
  "technologies": [
    { "name": "Cloudflare",   "categories": ["CDN"],                   "confidence": 100, "source": "http", "version": "", "cpe": "", "description": "...", "website": "https://www.cloudflare.com", "icon": "CloudFlare.svg" },
    { "name": "Google Cloud", "categories": ["Cloud hosting"],         "confidence": 70,  "source": "tls",  "version": "", "cpe": "", "description": "", "website": "", "icon": "" },
    { "name": "MySQL",        "categories": ["Databases"],             "confidence": 100, "source": "http", "version": "", "cpe": "cpe:2.3:a:mysql:mysql:*:*:*:*:*:*:*:*", "description": "...", "website": "https://mysql.com", "icon": "MySQL.svg" },
    { "name": "PHP",          "categories": ["Programming languages"], "confidence": 100, "source": "http", "version": "8.4.24", "cpe": "cpe:2.3:a:php:php:*:*:*:*:*:*:*:*", "description": "...", "website": "https://php.net", "icon": "PHP.svg" },
    { "name": "WordPress",    "categories": ["CMS", "Blogs"],          "confidence": 100, "source": "http", "version": "7.1", "cpe": "cpe:2.3:a:wordpress:wordpress:*:*:*:*:*:*:*:*", "description": "...", "website": "https://wordpress.org", "icon": "WordPress.svg" },
    { "name": "jQuery",       "categories": ["JavaScript libraries"],  "confidence": 100, "source": "http", "version": "4.0.0", "cpe": "cpe:2.3:a:jquery:jquery:*:*:*:*:*:*:*:*", "description": "...", "website": "https://jquery.com", "icon": "jQuery.svg" },
    { "name": "jQuery CDN",   "categories": ["CDN"],                   "confidence": 100, "source": "http", "version": "", "cpe": "", "description": "...", "website": "https://code.jquery.com/", "icon": "jQuery.svg" }
  ],
  "categories": {
    "Blogs": ["WordPress"],
    "CDN": ["jQuery CDN", "Cloudflare"],
    "CMS": ["WordPress"],
    "Cloud hosting": ["Google Cloud"],
    "Databases": ["MySQL"],
    "JavaScript libraries": ["jQuery"],
    "Programming languages": ["PHP"]
  },
  "meta": { "status_code": 200, "tech_count": 7, "scan_depth": "full" },
  "cached": false,
  "response_ms": 245
}

The categories map is the quickest way to answer the list-building question: .categories["CDN"] holds every CDN-category name, so jQuery CDN shows up there beside the infrastructure CDN (Cloudflare) that proxies the site. The two are independent signals and a site commonly has both. The meta object carries the HTTP status_code, the tech_count, and the scan_depth; cached and response_ms sit at the top level. Note the WordPress co-detection: jquery.com is a WordPress site whose theme loads jQuery from the CDN instead of the copy WordPress bundles, which is exactly the WordPress-plus-jQuery-CDN pattern you will see on a large share of hits. Google Cloud is the one entry not sourced from the HTML: it comes from the TLS layer at confidence 70, which is why it has no website or icon.

Shortcut: GET /check for a boolean

When you only need a yes-or-no answer for one technology, /check runs the same scan and returns a compact response. The technology name is matched case-insensitively and the space must be URL-encoded:

$ curl -s "https://detectzestack.p.rapidapi.com/check?url=jqueryui.com&tech=jQuery%20CDN" \
  -H "X-RapidAPI-Key: YOUR_KEY" \
  -H "X-RapidAPI-Host: detectzestack.p.rapidapi.com"
{
  "domain": "jqueryui.com",
  "technology": "jQuery CDN",
  "detected": true,
  "confidence": 100,
  "version": "",
  "categories": ["CDN"],
  "response_ms": 612,
  "cached": false
}

Ask for tech=jQuery instead and the same call returns "version": "4.0.0", because the version lives on the library entry. If you want both the host and the version in one request, use /analyze.

Build a Companies-Using-jQuery-CDN List With /analyze/batch

POST /analyze/batch accepts up to 10 URLs per request and scans them concurrently. Each item in results carries either a result object with the single-domain shape or an error string for domains that could not be fetched. This three-domain call mixes two jQuery CDN sites with one that is not:

$ curl -s -X POST "https://detectzestack.p.rapidapi.com/analyze/batch" \
  -H "X-RapidAPI-Key: YOUR_KEY" \
  -H "X-RapidAPI-Host: detectzestack.p.rapidapi.com" \
  -H "Content-Type: application/json" \
  -d '{"urls": ["jquery.com", "jqueryui.com", "getbootstrap.com"]}' \
  | jq '{successful, failed, total_ms,
         rows: [.results[] | {url,
           cdn: .result.categories["CDN"],
           jquery: ([.result.technologies[] | select(.name == "jQuery") | .version] | first),
           status: .result.meta.status_code}]}'
{
  "successful": 3,
  "failed": 0,
  "total_ms": 1310,
  "rows": [
    { "url": "jquery.com",       "cdn": ["jQuery CDN", "Cloudflare"], "jquery": "4.0.0", "status": 200 },
    { "url": "jqueryui.com",     "cdn": ["Cloudflare", "jQuery CDN"], "jquery": "4.0.0", "status": 200 },
    { "url": "getbootstrap.com", "cdn": ["Cloudflare", "Fastly"],     "jquery": null,    "status": 200 }
  ]
}

getbootstrap.com is a useful negative: it has two CDN-category entries and neither is jQuery CDN, and it has no jQuery entry at all, because Bootstrap 5 dropped the jQuery dependency. The filter has to look for the specific name, not just for anything in the CDN category.

Here is a complete pipeline in bash, curl, and jq. It reads domains.txt (one domain per line), sends batches of 10, writes one CSV row per jQuery CDN hit with the jQuery version and the co-detected CMS, and collects errors and partial scans into a retry file instead of treating them as negatives:

#!/usr/bin/env bash
# find-jquery-cdn.sh - build a jQuery CDN prospect list from domains.txt
KEY="YOUR_KEY"
HOST="detectzestack.p.rapidapi.com"

echo "requested,resolved,jquery_version,cms,tech_count" > jquery_cdn.csv
: > jquery_cdn_retry.txt

# 10 URLs per request is the /analyze/batch maximum
xargs -n 10 < domains.txt | while read -r batch; do
  urls=$(printf '%s\n' $batch | jq -R . | jq -s '{urls: .}')
  resp=$(curl -s -X POST "https://$HOST/analyze/batch" \
    -H "X-RapidAPI-Key: $KEY" \
    -H "X-RapidAPI-Host: $HOST" \
    -H "Content-Type: application/json" \
    -d "$urls")

  # One row per domain where jQuery CDN is in the technologies array
  echo "$resp" | jq -r '.results[]
    | select(.result != null)
    | . as $item
    | $item.result as $r
    | select([$r.technologies[].name] | index("jQuery CDN"))
    | [
        $item.url,
        $r.domain,
        (([$r.technologies[] | select(.name == "jQuery") | .version] | first) // ""),
        (($r.categories["CMS"] // []) | join(";")),
        ($r.meta.tech_count | tostring)
      ] | @csv' >> jquery_cdn.csv

  # Fetch errors and DNS-only scans are unknown, not negative
  echo "$resp" | jq -r '.results[]
    | select(.error != null or .result.meta.scan_depth == "partial")
    | .url' >> jquery_cdn_retry.txt

  sleep 1
done

echo "jQuery CDN hits: $(($(wc -l < jquery_cdn.csv) - 1))"

A 1,000-domain list is 100 batch calls. The index("jQuery CDN") guard keeps a domain only when the exact name appears, and the retry file catches the two cases that would otherwise poison the list: domains that failed to resolve, and scans where meta.scan_depth is "partial", meaning the HTTP fetch was blocked or timed out and only the DNS and TLS layers ran. Since jQuery CDN lives in the HTML body, a partial scan cannot see it. Throughput, retries, and a Python version of this loop are covered in how to batch scan 1,000 websites.

Querying already-scanned domains with /lookup

GET /lookup?tech=jQuery%20CDN returns domains where jQuery CDN was found in prior scans. It is a reverse index over DetectZeStack's own scan history, not a crawl of the web, so it is a way to seed a list rather than to enumerate every site on the internet. Results are paginated with limit and offset, and the limit is clamped per tier: 2 rows on the free tier, 50 on Pro, 200 on Ultra, and 800 on Mega.

$ curl -s "https://detectzestack.p.rapidapi.com/lookup?tech=jQuery%20CDN&limit=2" \
  -H "X-RapidAPI-Key: YOUR_KEY" \
  -H "X-RapidAPI-Host: detectzestack.p.rapidapi.com"
{
  "technology": "jQuery CDN",
  "total": 148,
  "limit": 2,
  "offset": 0,
  "results": [
    {
      "domain": "www.metavila.com.br",
      "category": "CDN",
      "confidence": 100,
      "version": "",
      "first_seen": "2026-08-04T12:14:37Z",
      "last_seen": "2026-09-10T18:02:00Z"
    },
    {
      "domain": "www.cardinaldigitalmarketing.com",
      "category": "CDN",
      "confidence": 100,
      "version": "",
      "first_seen": "2026-08-03T23:44:56Z",
      "last_seen": "2026-09-10T18:01:57Z"
    }
  ],
  "response_ms": 9
}

The total reflects how many domains in the scan history carry the signal at query time (148 as of this writing), and first_seen and last_seen tell you how fresh each row is. Treat it as a starting point and re-scan anything older than you are comfortable with.

Compare Competitors' jQuery Delivery With /compare

POST /compare takes two to ten URLs and returns each domain's full technology list, a shared array of names common to all of them, and a per-domain unique array. It is the fastest way to see whether two sites in the same market made the same delivery choice:

$ curl -s -X POST "https://detectzestack.p.rapidapi.com/compare" \
  -H "X-RapidAPI-Key: YOUR_KEY" \
  -H "X-RapidAPI-Host: detectzestack.p.rapidapi.com" \
  -H "Content-Type: application/json" \
  -d '{"urls": ["jquery.com", "getbootstrap.com"]}' \
  | jq '{shared, total_ms, domains: [.domains[] | {domain, unique}]}'
{
  "shared": ["Cloudflare", "Google Cloud"],
  "total_ms": 1102,
  "domains": [
    {
      "domain": "jquery.com",
      "unique": ["MySQL", "PHP", "WordPress", "jQuery", "jQuery CDN"]
    },
    {
      "domain": "getbootstrap.com",
      "unique": ["Astro", "Bootstrap", "Carbon Ads", "Fastly", "Fathom",
                 "GitHub Pages", "HSTS", "HTTP/3", "Varnish"]
    }
  ]
}

Read the unique arrays side by side and the two front-end philosophies are obvious: one site is a WordPress stack that pulls jQuery live from code.jquery.com, the other is a static Astro build on GitHub Pages with no jQuery anywhere. Add a third URL to the array and shared narrows to what all three have in common.

What a jQuery CDN Signal Tells You (and What It Does Not)

Combining with jQuery Migrate, WordPress, and Bootstrap

The jQuery CDN entry is most useful as one column in a wider segment. The same technologies array already carries the neighbours you need:

• jQuery CDN + jQuery Migrate is a legacy signal with a version attached. Migrate exists to keep pre-1.9 code running, so a site loading a current jQuery from the CDN and Migrate beside it has old plugin code it has not rewritten.
• jQuery CDN + WordPress means the theme or a plugin is deliberately swapping the bundled jQuery for the CDN copy. It is common on agency-built and theme-marketplace sites, and it is the single largest cohort you will find. See find companies using WordPress for that segment on its own.
• jQuery CDN + Bootstrap with a Bootstrap 3 or 4 version points to a jQuery-dependent Bootstrap build. Bootstrap 5 removed the dependency, so the combination dates the front end. Fingerprints are in how to detect Bootstrap.

Limits to keep in mind

Get Your API Key and Start Finding Companies Using jQuery CDN

The free tier includes 100 requests per month with no credit card. That is enough to validate the pipeline on a sample of your prospect list before scaling up:

1. Get a key at rapidapi.com/mlugoapx/api/detectzestack.
2. Spot-check a domain you know: curl -s "https://detectzestack.com/demo?url=jquery.com" | jq '.categories["CDN"]'
3. Run the batch script above against your first 100 domains and inspect jquery_cdn.csv and the retry file.

Conclusion

Finding companies using jQuery CDN comes down to one literal host name in the page HTML: code.jquery.com. DetectZeStack matches it, reports jQuery CDN under the CDN category, and adds the implied jQuery entry with its version and CPE. A single /analyze or /check call answers the one-domain question, /analyze/batch turns a domain list into a confirmed lead list with one jq filter, /lookup seeds that list from prior scans, and /compare puts two delivery strategies side by side. Swap the name in the filter and the same pipeline segments by Google Hosted Libraries, cdnjs, jsDelivr, or any other CDN-category entry.