Find out what a website is built with, from its CMS and analytics to its ad and marketing tools.
Technology lookup software reveals publicly detectable components of a website, including content management systems, analytics tags, frameworks, and marketing scripts. A quick browser extension is enough for checking one competitor, but prospecting teams often need lists of businesses using a particular product. Historical records and change alerts answer another question: when did the site adopt or remove a technology? Some researchers need code-pattern search rather than named software categories. These options are grouped by those research tasks, not presented as a universal ranking.
By SEM Solutions Editorial Team. Researched from vendor documentation, not hands-on testing. Ordered by Overall Score. Checked October 16, 2026. How we research
Historical Stack Research
#1 of 5 in Technology Lookup
BuiltWith provides technology profiles and historical detections for websites. Its Domain API exposes recorded stack information, while technology lists and change data support analysis across many domains. This helps researchers investigate platform adoption and migrations instead of looking only at today's website. The value lies in tracking changes over time and applying technology filters to company discovery.
Monitoring Technology Changes
#2 of 5 in Technology Lookup
Ful.io connects individual stack lookups to ongoing Technology Signals monitoring. Its reports can identify websites using a selected application, while alerts show when tracked domains add or remove detectable technologies. That is useful for timing sales research around apparent platform migrations. However, an observed change remains an external signal, not evidence of the business reason for a new installation.
Technographic Sales Lists
#3 of 5 in Technology Lookup
Wappalyzer detects website technologies using browser-observable signals such as headers, scripts, and page code. Its enrichment and prospecting products help teams use those detections to identify companies running particular software. Website alerts can surface adoption or removal events. For sales teams, the operational difference is turning a technology fingerprint into an actionable account segment rather than inspecting sites individually.
Exact Code Fingerprint Search
#4 of 5 in Technology Lookup
NerdyData permits searches for identifiable scripts, HTML fragments, cookies, and other code patterns rather than requiring a predefined software label. Its indexed website evidence can reveal companies using uncommon components that a categorical detector may not recognize. Analysts can then examine matching domains and technology trends. This method is particularly useful when a technical integration has a recognizable public signature.
One-Click Browser Inspection
#5 of 5 in Technology Lookup
WhatRuns identifies technologies on the website a researcher is currently viewing. Its extension reports visible frameworks, plugins, fonts, analytics tools, and hosting-related components after a browser click. A follow feature can notify users about later technology changes. For occasional competitor checks, this avoids building a bulk dataset or developer integration before getting an initial picture of a site's stack.
Ranked by Overall Score: our Editor Rating and Market Signal, 50/50. Market Signal uses Ahrefs and Semrush data through September 2026, pulled October 6 to 13, 2026. How we score
Website technology intelligence service for stack lookup, technology trends and lead lists.
Best for: Sales, competitive research, and data teams that need to identify website technology stacks or build lists by installed technology.
Website technology lookup with lead lists, technology change alerts, browser extensions and an MCP server.
Best for: Sales and agency teams prospecting companies by the software their websites run, such as stores on a specific ecommerce platform.
Identify the technologies websites are built with.
Best for: Sales, marketing and research teams that need technographic data.
Source code search engine that finds websites by technology, script, cookie or HTML snippet.
Best for: Sales and research teams building prospect lists of companies that run a specific script or tech stack.
Browser extension that reveals a site's CMS, frameworks, plugins, fonts and trackers in one click.
Best for: Developers, designers and marketers who want a quick look at another site's stack while browsing.
They inspect signals that websites expose publicly, including HTML, scripts, HTTP headers, and other implementation fingerprints. Wappalyzer and WhatRuns use these clues to label detectable technologies, while other platforms collect evidence across large domain sets. The resulting profile is an informed observation, not a complete inventory of every private service the organization uses.
Yes. BuiltWith and Wappalyzer offer technology-oriented lead research, while Ful.io can build technology reports. NerdyData offers a more specific approach by searching for code patterns associated with an integration. Coverage is limited to identifiable public evidence. A company might use software internally without exposing the fingerprints these services need to recognize it.
BuiltWith has historical technology information, Ful.io offers Technology Signals, and Wappalyzer documents change alerts. These can highlight visible adoption or removal of website services. Treat them as research prompts, not confirmation of a commercial contract change. A site can alter how it loads a script without actually replacing the underlying software.
Named technology detection depends on recognizable signatures that a tool associates with known products. Source code search lets a researcher specify an exact script, cookie, or HTML pattern, which helps with unusual or custom integrations. NerdyData covers that workflow. Both approaches can produce incomplete findings when implementation details are hidden from publicly accessible pages.
Yes, BuiltWith, Ful.io, Wappalyzer, NerdyData and WhatRuns all offer a free plan. Free tiers usually come with usage limits, so check whether they cover your volume before relying on them long-term.
Among the tools listed here whose main product is in this category and whose pricing we've verified, NerdyData has the lowest listed starting price: $50 per month (annual billing, $600/mo), billed annually. Starting price isn't the whole picture, so check what's included at that tier before deciding.