Website technology checker

Uncover the stack behind any website.

Analytics, CMS, frameworks, hosting, payments — detected across 21.8M sites, with the top 100k rescanned every week.

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A
atlasobscura.com
35 technologies in 17 categories · scanned Oct 24
Rank #1,458 · PageRank 8.4
Example
+ 9 more categories
sites analyzed
21.8M
technologies tracked
5,674
sites scanned in the last 7 days
2.1M
categories
104

Product

One registry, four ways in.

The same registry behind every report, ready for your pipeline, your watchlist, your comparisons and your AI tools.

Lead lists

Build lead lists

Combine technologies, rank range and language to list every matching site, then preview it for free before you generate the report.

Open the report builder
Watchlist

Watch competitors

Follow up to a handful of rivals: we rescan them every week and email you when a technology appears or disappears.

Start a watchlist
Compare

Compare technologies

Put two technologies side by side: adoption, market share and rank. Rivals in the same category also show the sites that run both.

Compare two technologies

GET /api/v1/domains/{domain}

Authorization: Bearer

Developers

Plug in the API & MCP

Query any domain or technology from your code, or ask Claude and other MCP clients directly. Free tokens every month.

Read the developer docs

Market share

Who leads the web.

The technologies found on the most sites in each category, among the top 10k, 100k and 1M sites by rank. Recomputed daily.

Usage is the share of crawled sites running each technology, out of the 1,332,651 that at least one ranking list places in the Top 1M.

See every category

Use cases

The data behind every product decision.

Sales, competitive intel, research and recruiting teams all start from the same question: what does this site run?

Sales

Prospect with intent.

Find every Shopify store, every HubSpot user, every Salesforce shop. Combine technologies, filter by language and rank, then generate the list.

Sales prospecting
Competitive intel

Watch your rivals' stack.

Follow competitors in your watchlist: we rescan them every week and email you when a technology is added or removed.

Competitive intel
Research

Measure the market.

See who leads each category across the top 10k, 100k and 1M sites, and how every technology spreads month by month.

Market research
Recruiting

Find the team.

Identify companies running your skill stack. React + Stripe is a conversation starter.

Recruiting

Website technology checker

What is a website technology checker?

A website technology checker inspects a site's pages, response headers and scripts to reveal the technologies it runs — its CMS, JavaScript frameworks, analytics, hosting, CDN and payment providers. LargerIO is a free website technology checker: enter any public domain and get a complete, categorised breakdown of its tech stack in seconds, backed by adoption data from millions of sites.

How it works

  1. 1

    Enter a domain

    Type any website address — like stripe.com — into the lookup field. No sign-up needed to run a check.

  2. 2

    We analyse the site

    LargerIO resolves the domain and inspects its pages, headers and scripts to fingerprint the technologies it runs.

  3. 3

    Read the tech stack

    Get a full profile in seconds — every detected technology, grouped by category, with adoption data across the web.

What technologies can it detect?

LargerIO detects thousands of technologies across dozens of categories, including:

  • Content management systems
  • Ecommerce & payments
  • JavaScript frameworks
  • Analytics & tag managers
  • CDNs & hosting
  • Web servers & languages

Browse the full technology registry, explore every category, or see who leads each category across the web.

Frequently asked questions

How do I check the technologies a website uses?

Enter any domain (for example stripe.com) in the lookup field above. LargerIO resolves the site, analyses its responses and lists every detected technology, grouped by category, with adoption data across the web.

Is the website technology checker free?

Yes. You can run lookups for free, with no account required to get started. To automate checks, a free verified account also gets 2,000 REST API and MCP tokens every month.

How fresh is the data?

Sites ranked in the top 100k are rescanned every week and the top million every two weeks; the rest of the registry is refreshed every few months. A lookup scans the site live, and results are cached for a few hours.

Can I get alerted when a competitor changes its stack?

Yes. Add competitors to your watchlist with a free account: we rescan them every week and email you a summary when a technology is added or removed.

Is there an API or an MCP server?

Yes. A free verified account gets 2,000 REST API and MCP tokens a month to look up domains and technologies from your code or from AI assistants such as Claude.

Start for free

No card. Free to get started.

Look up any site from the browser, your IDE or a script. Reports are generated for free; paid downloads open soon.

Create your free account Read the API docs →
10
lookups / minute on the website, no sign-up
2,000
REST API and MCP tokens / month with a free verified account
1 · 5 · 100
tokens for a technology's top sites, a quick lookup, a full lookup
50
report generations / month on a free account

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