Fetches one page from our server and lists the hosting, CDN and payment technologies that its response headers and script addresses reveal, from a short list of signatures taken from each vendor's own documentation. For founders and marketers who want to know what a competitor's page, or their own, runs on. It says which technologies it found, which it looked for and did not see, and how short the list is.
How to use it
Enter the address of a public page, such as a home page. You can leave out https://.
- Type or paste the address of the page and press Run check.
- Read the technologies under Detected, with the signal that revealed each one.
- Check the ones listed as looked for and not seen, and remember that this is not proof they are absent.
- Copy the result if you want to keep it, or run another page.
How Reavlo tests this
Coverage. The tool checks three technologies today: Cloudflare, Vercel and Stripe.js. That is a deliberately short list, not a catalogue of everything a site can run. It does not detect content management systems, front-end frameworks, analytics or advertising tools; for the measurement tags a page loads, use the tracking tag checker. The list grows only when a vendor's official documentation has been read and the signature verified.
Where signatures come from. Every signature is written by us from the vendor's official documentation, and each result shows the document and the date it was read: Cloudflare's HTTP headers (the cf-ray header), Vercel's response headers (the x-vercel-id header) and Stripe's guide to including Stripe.js (the script address js.stripe.com). We do not copy a third-party database of fingerprints. The list is reviewed every quarter.
What it reads. One request to the page, with up to 3 redirects, a size cap and a time limit. It reads the response headers and the script addresses in the HTML as the server sent them, and runs no script. A technology loaded only after the page runs, or only on another page, is not seen. Addresses that point to private or internal networks are refused before any connection is made.
Three answers, kept apart. Detected means a documented signature was seen. Not seen means it was looked for and not found, which is not proof that the technology is absent: a site can hide a header or load the technology elsewhere. Could not be judged means the page did not answer normally or its HTML was cut short, so the signature could not be checked.
Confidence. A technology with two or more matching signals is shown with high confidence, and one with a single signal with medium confidence. Today each technology has a single signature, so a detection is medium confidence.
This tool runs on our server, because a browser cannot read another site's response headers. Nothing about the request is stored or logged: not the address, not the page.
Questions
Why does it say a technology was not seen when I know the site uses it?
The tool looks for one documented signal per technology, such as a response header. If the site hides that header, or loads the technology only after the page runs, it is not seen. Not seen is never proof of absence.
Which technologies can it detect?
Cloudflare, Vercel and Stripe.js. The list is short on purpose: a signature is added only after the vendor's official documentation has been read and the signature verified. Content management systems, frameworks and analytics tools are not covered.
Where do the signatures come from?
From each vendor's own documentation, written by us, with the document and the date it was read shown next to every result. We do not copy a third-party database.
Is the address I enter stored?
No. The address goes to our server only to fetch the page, and neither it nor the page is stored or written to a log. Analytics records only that the tool ran, never the address.
Can I use this to see which tracking tags a page loads?
Not here. This tool covers hosting, CDN and payment technologies. For analytics, ad and consent tags, use the tracking tag checker.