Open source BuiltWith alternative: looot-techstack
Find the technologies a website uses, and the companies that use a technology.
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.
Short answer
What is looot-techstack?
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
What looot-techstack does and how to run it
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.
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-runFacts
Facts from the repository
Read from GitHub on 2026-10-11.
| Job | Find the technologies a website uses, and the companies that use a technology. |
|---|---|
| License | MIT |
| Language | TypeScript |
| A real run needs |
|
| 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 | github.com/loootai/looot-techstack |
| Facts read on | 2026-10-11 |
Data and price
Endpoints it calls, with the live price
Every real run calls these looot endpoints. The price column is read live from the catalog, never typed into this page.
| Endpoint | Used for | Live price |
|---|---|---|
| builtwith-free1-api-jsonbuiltwith | Category counts with first and last seen, no technology names | reading live price |
| tomba-technologytomba | Technologies with categories | reading live price |
| predictleads-companies-technology-detectionspredictleads | Technologies with first and last seen | reading live price |
| builtwith-api-jsonbuiltwith | Full profile, live and dead technologies (off by default) | reading live price |
| theirstack-companies-technologiestheirstack | Technologies read from job posts, with a confidence level (off by default) | reading live price |
| builtwith-lists12-api-jsonbuiltwith | Find companies that use a technology | reading live price |
| predictleads-discover-technologies-technology-detectionspredictleads | Find companies that use a technology, after a name lookup | reading live price |
Prices are read from the looot public catalog when the page loads. Some endpoints are priced per result, so a run that returns many rows costs more than one call. The CLI dry run prints the exact quote for your input before anything is charged.
Limits
What looot-techstack 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.
With an agent
Run it with your agent
Copy the prompt, give it to the agent you already use, and it dry-runs first.
FAQ
Questions about looot-techstack
Keep going
Related on looot.ai
- Can an agent replace BuiltWith?
Job by job, with live prices
- BuiltWith through looot
Website technology lookup API
- Tomba through looot
Email finder and verifier
- Free tools
Jobs you can run in the page
- All open source repos on looot
The hub with every repo
- repo
- https://github.com/loootai/looot-techstack
- job
- Find the technologies a website uses, and the companies that use a technology.
- license
- MIT
- language
- TypeScript
- endpoint
- builtwith: builtwith-free1-api-json (company_technographics)
- endpoint
- tomba: tomba-technology (company_technographics)
- endpoint
- predictleads: predictleads-companies-technology-detections (company_technographics)
- endpoint
- builtwith: builtwith-api-json (company_technographics)
- endpoint
- theirstack: theirstack-companies-technologies (company_technographics)
- endpoint
- builtwith: builtwith-lists12-api-json (lists12_api-json)
- endpoint
- predictleads: predictleads-discover-technologies-technology-detections (discover_technologies_technology-detections)
- price
- per call, read live from the catalog on the web page
- framing
- MIT code, paid data, every real run calls looot
- setup
- https://looot.ai/skill.md
- llms.txt
- https://looot.ai/llms.txt
- read
- 2026-10-11
Run looot-techstack on your own looot account.
Try the demo first, no account needed. For a real run, start your workspace, top up, and use the quote the repo prints before it spends anything.