Stack Lookup

Stack Lookup answers which companies run which technologies, since when, and what changed. Most technology lookups stop at a domain. Stack Lookup resolves the domain to the company behind it and serves that company's whole stack across every host it owns, so a question about a business gets an answer about the business rather than about one web server. The index covers 53,578,213 companies and 8,177 technologies, verified continuously since 2020. Every technology carries a first and last verified date, the hosts it was seen on and a verification count, so an assistant can say when something was observed instead of asserting it as a timeless fact. Counts are exact over the whole index: no sampling, no extrapolation. Eight read-only tools: look up a domain or a company; count and list companies matching a technology and firmographic filter (technologies all/any/none, HQ country, NAICS, ISIC, NACE, UK SIC, Veridion business category, employee band); profile a technology and its adoption by country, industry and company size; find companies first verified on a technology since a date; compare up to ten stacks side by side; and check your own credit balance. Four prompts cover the common jobs: researching a company's stack, building a target list, detecting replatforming, and sizing a technology's market share. Free keys include 5,000 credits a month. Counting, technology profiles and usage checks cost nothing, so a list can be sized before any of it is paid for. Data by Veridion.