How to Detect LiteSpeed Cache on Any Website (2026 Guide)

LiteSpeed Cache is one of the most widely installed performance plugins in the WordPress ecosystem, and it is unusually talkative about itself. When it is running, it usually says so in the HTTP response headers, and when it does not, it tends to leave its script path in the HTML. That makes it one of the easier caching layers to detect from outside—once you know which signal to read, what its value means, and the handful of situations where it goes quiet.

This guide covers the difference between LiteSpeed Cache and the LiteSpeed web server, the three signals that reveal the cache, how to check them by hand with curl, why a cache miss or a CDN changes what you see, and how to detect LiteSpeed Cache on one site or a thousand with the DetectZeStack API.

What LiteSpeed Cache Is (and How It Differs From the LiteSpeed Web Server)

The names overlap, so it is worth separating them up front. LiteSpeed is a web server—an Apache-compatible alternative available as the commercial LiteSpeed Enterprise and the open-source OpenLiteSpeed. LiteSpeed Cache, often shortened to LSCache, is the full-page cache built into that server. They are related, but they are not the same detection, and they do not answer the same question.

LSCache as a WordPress Plugin vs Server-Level Caching

The cache engine lives in the server, but on WordPress it is controlled by the LiteSpeed Cache plugin. The plugin tells the server which pages are cacheable, tags them so they can be purged when content changes, and layers on its own optimizations such as CSS and JavaScript minification, image optimization, and lazy loading. Other platforms have their own LSCache integrations, but WordPress is where the overwhelming majority of installs sit.

That split has a practical consequence for detection. The web server tells you what the host chose. The cache tells you something closer to what the site owner chose: somebody installed or kept the plugin, and the server is actually caching pages for them.

Why Detection Matters for Agencies, Hosting Sales, and Competitive Research

• WordPress agencies auditing a prospect's site want to know whether a page cache is already in place before quoting a speed-optimization engagement, and whether a second caching plugin would conflict with it.
• Hosting and migration sales teams use LiteSpeed Cache as a marker of a LiteSpeed-based host. A prospect on LiteSpeed with the cache running is on a performance-oriented stack already; one moving away from it needs a replacement cache story.
• Competitive research is simpler: if three competitors all run LiteSpeed Cache on WordPress, you have learned what hosting tier and performance stack your market settled on.

The Signals That Reveal LiteSpeed Cache

There are three signals DetectZeStack matches for LiteSpeed Cache, plus one related signal that identifies the server rather than the cache.

The x-litespeed-cache Response Header (hit, miss, and no-cache Values)

The strongest signal is the x-litespeed-cache header. It is non-standard, it is vendor-specific, and nothing but LSCache sends it. Here is a real response from openlitespeed.org:

$ curl -sI https://openlitespeed.org | grep -iE "^(server|x-litespeed)"
server: LiteSpeed
x-litespeed-cache: hit

The value describes what happened to this request. hit means the page came out of the cache without touching PHP. miss means it was not cached and had to be generated. You may also see other values depending on which cache layer answered—LiteSpeed's own QUIC.cloud site returned x-litespeed-cache: bkd when we checked it. For detection, the value is irrelevant: the fingerprint matches on the header's presence, so a hit, a miss, and anything else all count.

The x-turbo-charged-by: LiteSpeed Header

Many LiteSpeed-based hosts add x-turbo-charged-by: LiteSpeed to every response. DetectZeStack treats this header as a LiteSpeed Cache signal, and it matters most in exactly the case where the other signals disappear: a CDN in front of the origin. Here is a real host behind Cloudflare:

$ curl -sI https://chemicloud.com | grep -iE "^(server|x-turbo|x-litespeed|cf-cache)"
server: cloudflare
x-turbo-charged-by: LiteSpeed
cf-cache-status: DYNAMIC

No x-litespeed-cache, and the Server header names Cloudflare. The x-turbo-charged-by header came straight through from the origin anyway.

Script Paths Under wp-content/plugins/litespeed-cache/

The third signal lives in the HTML rather than the headers. When the plugin loads its own front-end assets—lazy-loading scripts, for example—they are served from /wp-content/plugins/litespeed-cache/. A <script src> pointing there proves the WordPress plugin is installed, even on a request where the cache headers are absent. It is also the one signal that does not depend on how the response was cached.

Server: LiteSpeed and Why It Implies the Server, Not the Plugin

Server: LiteSpeed is the most visible LiteSpeed signal, and it is the one most often misread. It identifies the web server. It says nothing about whether LSCache is enabled or whether the WordPress plugin is installed. Plenty of LiteSpeed-hosted WordPress sites never activate the plugin, and plenty of non-WordPress sites run on LiteSpeed. In DetectZeStack results this signal produces a separate technology named LiteSpeed in the Web servers category, never LiteSpeed Cache.

Manual Detection With curl and Browser DevTools

Reading Response Headers With curl -I

One command checks both header signals and the server at once:

curl -sI https://example.com | grep -iE "^(server|x-litespeed|x-turbo-charged-by)"

If that prints nothing LiteSpeed-related, check the HTML for the plugin path:

curl -sL https://example.com | grep -o 'wp-content/plugins/litespeed-cache/[^"]*' | sort -u

In browser DevTools, the same information is on the Network tab: select the document request and read the response headers, then search the Sources or Elements panel for litespeed-cache.

Why a Cache MISS or a Logged-In Session Can Hide the Header

The header is only as reliable as the request that produced it. We added a random query string to openlitespeed.org, which forces a URL the cache has not seen, and the x-litespeed-cache header was no longer in the response:

$ curl -sI "https://openlitespeed.org/?nocache=12345" | grep -iE "^(server|x-litespeed)"
x-litespeed-cache-control: public,max-age=604800
x-litespeed-tag: 3f0_front,3f0_URL.6666cd76f96956469e7be39d750cc7d9,3f0_F,3f0_Po.8659,3f0_PGS,3f0_
server: LiteSpeed

Two lessons come out of that output. First, do not add cache-busting parameters when you are testing for a cache—request the plain URL the way a normal visitor would. Second, even on an uncached request LSCache left x-litespeed-cache-control and x-litespeed-tag behind. Those are useful for a human reading the headers, but they are not part of the detection fingerprint, so a scan of that exact request would have to fall back on the plugin script path.

Logged-in sessions behave the same way. WordPress administrators, and anyone carrying a login or cart cookie, are typically served uncached pages, so checking your own site from a browser where you are logged in to wp-admin is a common way to convince yourself the cache is not working. Test from a private window or from curl, which carries no cookies.

Edge Cases: CDNs, Cloudflare, and QUIC.cloud in Front of the Origin

Every external check sees the outermost hop. A CDN rewrites Server to its own name, and some also strip or cache headers from the origin. Three situations cover most of what you will see:

• Cloudflare in front. The Server header says cloudflare, but vendor headers such as x-turbo-charged-by and x-litespeed-cache are usually passed through, as the chemicloud.com example shows.
• QUIC.cloud in front. QUIC.cloud is LiteSpeed's own CDN and is designed to cache LSCache pages at the edge, so the LiteSpeed headers survive. DetectZeStack identifies QUIC.cloud separately through DNS, when the domain's CNAME points at a .quic.cloud host.
• A strict edge that strips unknown headers. Here the headers are gone, and the plugin script path is the only remaining signal. If the site does not load any plugin assets on the page you scanned, the cache is invisible from outside. Treat that as unknown, not as a confirmed absence.

For more on what the edge layer reveals on its own, see how to detect the CDN and hosting provider of any website.

Detect LiteSpeed Cache With the DetectZeStack API

The DetectZeStack API reads HTTP headers, HTML, DNS records, and TLS certificates in a single call and returns every detected technology as structured JSON. LiteSpeed Cache is matched on all three signals above and returned in the Caching and WordPress plugins categories.

Try It Without a Key: GET /demo

The public /demo endpoint needs no API key. It is rate-limited per IP, so use it for spot checks, not bulk scans. This is a real response, filtered to the LiteSpeed entries:

$ curl -s "https://detectzestack.com/demo?url=openlitespeed.org" \
  | jq '.technologies[] | select(.name | ascii_downcase | startswith("litespeed"))'
{
  "name": "LiteSpeed",
  "categories": ["Web servers"],
  "confidence": 100,
  "description": "LiteSpeed is a high-scalability web server.",
  "website": "https://litespeedtech.com",
  "icon": "LiteSpeed.svg",
  "cpe": "cpe:2.3:a:litespeedtech:litespeed_web_server:*:*:*:*:*:*:*:*",
  "source": "http"
}
{
  "name": "LiteSpeed Cache",
  "categories": ["Caching", "WordPress plugins"],
  "confidence": 100,
  "description": "LiteSpeed Cache is an all-in-one site acceleration plugin for WordPress.",
  "website": "https://www.litespeedtech.com/products/cache-plugins/wordpress-acceleration",
  "icon": "LiteSpeed.svg",
  "source": "http"
}
{
  "name": "Litespeed Cache",
  "categories": ["Caching", "WordPress plugins"],
  "confidence": 100,
  "description": "LiteSpeed Cache is an all-in-one site acceleration plugin for WordPress.",
  "website": "https://wordpress.org/plugins/litespeed-cache/",
  "icon": "litespeed-cache.png",
  "source": "http"
}

Single Site: GET /analyze?url=example.com

The authenticated /analyze endpoint returns the same shape through RapidAPI. The technologies array is what you filter on—each entry carries name, categories, confidence, and source—and the categories map is the fastest way to read a whole result. This is a real scan of the Cloudflare-fronted host from earlier (we ran it through /demo, which returns the same response shape):

$ curl -s "https://detectzestack.p.rapidapi.com/analyze?url=chemicloud.com" \
  -H "X-RapidAPI-Key: YOUR_KEY" \
  -H "X-RapidAPI-Host: detectzestack.p.rapidapi.com" \
  | jq '{domain, categories: {CDN: .categories.CDN, Caching: .categories.Caching, "Web servers": .categories["Web servers"]}, meta, cached, response_ms}'
{
  "domain": "chemicloud.com",
  "categories": {
    "CDN": ["Cloudflare"],
    "Caching": ["Litespeed Cache", "LiteSpeed Cache"],
    "Web servers": ["LiteSpeed"]
  },
  "meta": {
    "status_code": 200,
    "tech_count": 13,
    "scan_depth": "full"
  },
  "cached": false,
  "response_ms": 2575
}

Cloudflare is in the CDN category because that is what the Server header said. LiteSpeed Cache is still detected because x-turbo-charged-by leaked through the edge, and LiteSpeed shows up in Web servers even though the Server header never named it. The next section explains why.

Many Sites at Once: POST /analyze/batch

POST /analyze/batch accepts up to 10 URLs per request. Each entry in results[] carries either a result with the same shape as a single /analyze response, or an error string. This prints one line per domain with a yes/no for LiteSpeed Cache:

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": ["openlitespeed.org", "chemicloud.com", "wordpress.org"]}' \
  | jq -r '.results[]
      | select(.result != null)
      | .result
      | [ .domain,
          ([.technologies[].name | ascii_downcase] | index("litespeed cache") != null) ]
      | @tsv'

Domains that fail to fetch are skipped by the select(.result != null) guard. For a full list-processing script with batching, retries, and CSV output, see how to batch scan 1,000 websites.

Side by Side: POST /compare

To see which competitors run LiteSpeed Cache and which do not, POST /compare takes 2 to 10 URLs and returns each domain's technologies, a per-domain unique array, and a top-level shared array:

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": ["competitor-one.com", "competitor-two.com", "competitor-three.com"]}' \
  | jq '[.domains[] | {domain, litespeed_cache: ([.technologies[].name | ascii_downcase] | index("litespeed cache") != null)}]'

If LiteSpeed Cache appears in shared, every site in the comparison runs it. For the wider workflow, see competitor website technology analysis.

Interpreting Results: LiteSpeed Cache Implies LiteSpeed

The LiteSpeed Cache fingerprint declares an implies relationship to LiteSpeed. Whenever the cache is detected, the web server is added to the results too, which is correct: LSCache only runs on a LiteSpeed server. That is how chemicloud.com ends up with LiteSpeed in Web servers despite a Server: cloudflare header.

Read the combinations like this:

The third row is the subtle one. Because x-turbo-charged-by is a host-level header, a match on it alone confirms LiteSpeed caching infrastructure but not the WordPress plugin specifically. The chemicloud.com scan is exactly that case: LiteSpeed Cache is reported, WordPress is not. If you specifically need the plugin, require WordPress in the same result, or confirm the litespeed-cache script path. Our guide to checking whether a website uses WordPress covers that half of the check.

LiteSpeed Cache vs Other Caching Layers (Varnish, CDN Edge Caching)

LiteSpeed Cache is one of several caching layers a site can run, and each identifies itself differently:

• Varnish is a standalone reverse caching proxy that sits in front of any web server. It is detected through its own headers—x-varnish, or a Via header naming Varnish—and appears as a separate Varnish technology in the Caching category. See finding companies using Varnish.
• CDN edge caching from Cloudflare, Fastly, or CloudFront caches responses at the edge and reports its own status in headers like cf-cache-status. These are detected as CDNs, not as page caches, and they frequently stack on top of LSCache.
• Plugin-only caches such as WP Rocket work on any web server and do not require LiteSpeed at all.

A site can run more than one of these at once. The chemicloud.com scan shows LiteSpeed Cache at the origin and Cloudflare at the edge in the same result. For the web-server view of the same population, see finding companies using LiteSpeed.

Get Your API Key

The free tier includes 100 requests per month with no credit card, which is enough to check a sample of your list before scaling up:

1. Get a key at rapidapi.com/mlugoapx/api/detectzestack.
2. Spot-check a site you know: curl -s "https://detectzestack.p.rapidapi.com/analyze?url=yourdomain.com" -H "X-RapidAPI-Key: YOUR_KEY" -H "X-RapidAPI-Host: detectzestack.p.rapidapi.com" | jq '.categories.Caching'
3. Run the batch example above against your first 10 domains.

Conclusion

Detecting LiteSpeed Cache comes down to three signals: the x-litespeed-cache header, the x-turbo-charged-by: LiteSpeed header, and the wp-content/plugins/litespeed-cache/ script path. The header value, whether hit or miss, does not matter; its presence does. Server: LiteSpeed identifies the web server, not the cache. A cache-busted URL, a logged-in session, or a strict CDN can hide the headers, so a negative result is weaker evidence than a positive one.

Check one site with /demo, many with /analyze/batch, and match the name case-insensitively so the LiteSpeed Cache / Litespeed Cache duplicate does not skew your counts.