# Open source BuiltWith alternative: looot-techstack The code is MIT open source. The data is not free and not self-hosted: every real run calls looot and pays per call at the catalog price shown before the run. Find the technologies a website uses, and the companies that use a technology. ## Short answer looot-techstack is an MIT-licensed web app and CLI that asks several technology data providers what a company website runs on, then shows their answers side by side with how far they agree. It also finds companies that use a given technology. The code is open source. The data is paid per looot call. ## What it does It sends each domain to up to five technology providers through the looot job company.technographics. You see the technologies by category, which providers named each one, how many of the providers that returned a list agree, and first and last seen dates where a provider gives them. A second search runs the other way. Give it a technology name and it asks for companies that use it, and it returns the provider's first page of results. Answers are stored in a local file for 30 days, so asking again about the same domain makes no new call. The quote prints before any paid action, and a spend cap stops the run before a call that would pass it. This is the job that products such as BuiltWith and Wappalyzer do. ## Commands git clone https://github.com/loootai/looot-techstack && cd looot-techstack npm install --ignore-scripts npm run demo npm run techstack -- --domains examples/domains.csv --dry-run LOOOT_TOKEN=... npm run techstack -- --domain stripe.com --providers builtwith-free,tomba,predictleads,builtwith npm run techstack -- --find HubSpot --dry-run ## Facts - Job: Find the technologies a website uses, and the companies that use a technology. - License: MIT - Language: TypeScript - Needs: Node.js 22.12 or newer - Needs: A looot token with the scopes runs.execute, catalog.read, runs.read and usage.read, for real lookups only - Needs: A funded looot balance, for real lookups only - Demo mode: Yes. npm run demo opens a web app with made-up companies and fixture answers. It needs no token and costs nothing. A dry run quotes a file of domains without a token. - Repository: https://github.com/loootai/looot-techstack ## Endpoints it calls - builtwith: builtwith-free1-api-json (company_technographics), Category counts with first and last seen, no technology names - tomba: tomba-technology (company_technographics), Technologies with categories - predictleads: predictleads-companies-technology-detections (company_technographics), Technologies with first and last seen - builtwith: builtwith-api-json (company_technographics), Full profile, live and dead technologies (off by default) - theirstack: theirstack-companies-technologies (company_technographics), Technologies read from job posts, with a confidence level (off by default) - builtwith: builtwith-lists12-api-json (lists12_api-json), Find companies that use a technology - predictleads: predictleads-discover-technologies-technology-detections (discover_technologies_technology-detections), Find companies that use a technology, after a name lookup ## What it does not do - It detects nothing itself. It asks providers and compares their answers. It runs no crawler, keeps no fingerprint database and has no browser extension. - The free provider returns category counts only, without technology names. - A find-companies search returns the provider's first page of results, not every site that uses the technology. - Names are matched after case, punctuation and a short alias list are normalised. A provider that spells a product differently shows as a second technology. - Response parsing was written from provider documentation and fixtures. The README says it was not checked against a recorded paid response, so expect to adjust a parser after your first real run. A field it cannot find stays blank. - The web app has no sign-in and keeps its answers in a file on disk, so it needs a host with a persistent disk and your own access control. ## Run it with an agent Use looot to find the technologies used by the company domains in my file. Read https://looot.ai/skill.md first. Then clone https://github.com/loootai/looot-techstack, run its dry run on my domains file and show me the quote and the spend cap. Run the real lookup only after I say yes, and report each technology with the providers that named it. ## What does looot-techstack do? It looks up the technologies a website uses and lists the companies that use a given technology. It asks several data providers through looot and shows their answers side by side, with the providers that named each technology. ## Is looot-techstack free? The code is free under the MIT license. The data is not. Every real lookup is a paid looot call at the catalog price, which the CLI quotes before it runs. The demo mode and the dry run cost nothing. ## Can I try it without a looot account? Yes. npm run demo shows made-up companies with fixture answers, and --dry-run prints the quote for a file of domains. Both need no token. A real lookup needs a token and a funded balance. ## What does one lookup cost? The table on this page shows the live catalog price of each endpoint it calls. One domain costs the sum of the providers you switch on. The quote printed by --dry-run adds it up for your whole file. ## Which providers does it ask? Three providers are on by default and the first is free. Two more paid providers are optional and off by default. A reverse search uses one of two more endpoints. The table on this page lists each endpoint with its live price. ## What does it not do? It runs no crawler of its own and has no browser extension. The free provider gives category counts only, and a find-companies search returns the first page of results. The README also says parsers were not checked against recorded paid responses. ## Do I have to host it myself? You run it yourself, on your machine or on a host with a persistent disk. The web app keeps its answers in a JSON file and has no sign-in, so put it behind your own access control. ## How do I run it from an agent? Give your agent the prompt on this page and the setup link https://looot.ai/skill.md. The repo also ships a Claude Code skill that dry-runs first, keeps paid providers opt-in and never raises the cap on its own. ## Related - /open-source-alternatives - /can-i-replace/builtwith - /mcp/builtwith - /mcp/tomba - /free-tools ## Last read 2026-10-11. Facts come from the repository on GitHub. The price per call is read live from the catalog on the web page.