Tellstack
Find out what any website is built with: its CMS, shop, analytics, CDN, host, mail provider and 7,600 other technologies, each with a version, a confidence score and the evidence that gave it away. A BuiltWith or Wappalyzer alternative priced for people who aren’t enterprises.
Lookups with evidence
GET /v1/lookup?domain= returns every technology with the header, cookie, script, meta tag, DNS record or certificate behind it.
Bulk jobs
Up to 10,000 domains at once, as CSV or JSON in and out.
Sites using X
Lists of sites using a technology from our own index, ranked by popularity and filtered by domain ending and first-seen date.
Watches and webhooks
Hear when a site changes its stack, or when a new site starts using a technology, by signed webhook.
Getting started
- Open tellstack.onibaku.co.uk and sign in with your email.
- Look up a domain in the dashboard, or create an API key and call
/v1/lookup. - The API reference and OpenAPI spec cover jobs, lists, watches and webhooks.
Pricing
- Free: 100 credits and 10 watches a month, and the top 25 rows of any list. No card.
- Pro: £49 a month for each block of 10,000 credits and 500 watches, or £41 a month billed yearly. £39 a block from 5 blocks.
- A credit is one domain lookup or 10 list rows.
- Refunds within 14 days: email admin@onibaku.co.uk.
The crawler
The index is built by TellstackBot, which obeys robots.txt, identifies itself and stops at the first sign a site doesn’t want it. Site owners can opt out or ask for removal: see the bot page.
Privacy and terms
See the Tellstack section of our privacy policy and terms. Detection uses the GPL-3 webappanalyzer fingerprint data. Tellstack is independent and isn’t affiliated with Wappalyzer or BuiltWith.