893 technologies. Millions of sites. Refreshed daily.
Find out what any
website is built with.
See the full tech stack behind any website, and every company that uses a given technology.
One dataset, two ways to search.
Both run on the same live index.
StackSherlock API
Query the index directly via our REST API. Look up any domain's stack, or list every site running a technology. Python and TypeScript SDKs included.
View the API
StackSherlock Explorer
Search any domain and see its detected stack instantly, or browse by technology. No setup required.
Open Explorer
See any company's full stack in one search.
Most tools scan one page and guess. StackSherlock follows every request a site makes (scripts, pixels, fonts, tag managers and APIs) and maps each one to the company behind it. You see not just what a site loads, but who it is built with, down to the version.
Clean results, ready to drop into your CRM.
StackSherlock returns structured JSON by default: every technology with its category, vendor, version and the evidence behind it. Aliases and duplicates are merged, so GA4 and Google Analytics resolve to one entry. Drop it straight into a database, a dashboard, or your CRM.
Open Explorer
We catch the tools other scanners miss.
StackSherlock sees the tools other tools miss: anything loaded by a tag manager, a lazy-loaded script, or a single-page app. Sites that block bots are handled for you. Every detection comes with the exact signal that triggered it, so you can trust what you see.
Open ExplorerEverything your team needs to act on it.
Refreshed continuously
The index refreshes from new Common Crawl snapshots and Certificate Transparency feeds, so coverage grows every single day.
Built for the whole web
Hundreds of millions of domains in scope, with live on-demand lookup for anything not yet cached.
Your lookups stay private
The domains you look up are never sold or shared. Everything is encrypted in transit and at rest.
A catalog that grows itself
New tools are discovered automatically from the request graph, so the catalog expands without hand-written rules.
Every result, traceable to its source.
Every technology we report links to the exact signal that triggered it: the script URL, header, cookie or meta tag. Related and duplicate tools are canonicalized, so you never see the same product under three different names. You can trace any detection back to its source before you trust it.
See how detection works
Every detection links to its source
Domains analyzed and counting
Technology detections
Technologies detected
Latest Updates
Read our latest update
How to find out what a website is built with
Four ways to find the tech stack behind any website, from the browser network tab to a one-click lookup, with a method comparison and a view of when each one fits.
The AI tools websites are quietly adding in 2026
Support bots, AI on-site search and recommendation engines are spreading fast across the web. Where AI tools are showing up, why, and how to detect them on any site.
The most popular JavaScript frameworks right now
React leads new builds, jQuery still runs the long tail, and meta-frameworks are the real story. A practical look at the JavaScript framework landscape, and how to tell which one a site uses.
Simple, transparent pricing.
Plans for the API, reverse lookups and exports. About half what the legacy tools charge, refreshed every day.
Starter
For individuals and small teams.
Billed monthly
- 25K API lookups / month
- Then $0.40 per 1K lookups
- Full REST API access
- Reverse "who-uses-X" lookups
- CSV / JSON exports
- Daily-refreshed data
- Detection evidence
Pro
For teams and researchers.
Billed monthly
- 150K API lookups / month
- Then $0.30 per 1K lookups
- Everything in Starter
- Bulk domain lookups
- Canonicalized results
- Live on-demand rendering
- Priority email support
Scale
For high-volume data teams.
Billed monthly
- 750K API lookups / month
- Then $0.20 per 1K lookups
- Everything in Pro
- Full REST API + webhooks
- Custom export schemas
- 99.9% uptime SLA
- Priority support · 8h response
Enterprise
Custom limits, SSO, dedicated infrastructure and a support SLA built around your team.
Common Questions
Some queries we usually get
StackSherlock builds its index from Common Crawl, Certificate Transparency logs and the Internet Archive, then renders pages live to confirm what each site actually loads. It refreshes continuously, so the catalog keeps growing on its own.
Yes. Upgrade, downgrade or cancel whenever you like. Changes take effect immediately and we prorate the difference.
We render it live on demand. The first lookup may take a few seconds while we fetch and analyze the site, then it's cached so the next lookup is instant.
Yes. Switch to yearly billing to get two months free on any paid plan.
No. The directory is free to browse without signing up. You only need an account for API access and exports.
Your lookups are never sold or shared. We use them only to serve your results, and everything is encrypted in transit and at rest.
Over 118,000 technologies across frameworks, analytics, pixels, payments, CMS and hosting, canonicalized so each tool resolves to a single entry.
Every technology we report links to the exact signal that triggered it (the script URL, header, cookie or meta tag) so you can verify any detection yourself.
Yes. Browse and search the directory in your browser, or export results as CSV, no code required. The REST API is there when you want to automate.