Wilder Labs Studio / Business Tools
What is my website built on?
Type a web address. We read what the site tells every visitor’s browser and say, in plain words, what it runs on and which support dates apply. Free, and the address isn’t saved.
Works with any public address, like example.com or www.example.com/shop.
How the check works
When a browser opens a web page, the server sends a few lines of information before the page itself. Many servers put their name and version there, like Microsoft-IIS/8.5 or PHP/8.2. Some sites also set cookies whose names give the software away, and older Microsoft sites often have page addresses ending in .asp or .aspx.
The check loads the one page you typed, follows any redirects and reads those clues. It doesn’t log in, fill in forms or open other pages, so the site sees one ordinary visit.
Reading the result
Classic ASP and ASP.NET Web Forms sites can run for years. What decides how long is the Windows Server underneath. IIS 8.5 means Windows Server 2012 R2, which is past support. IIS 10 could be Windows Server 2016, 2019, 2022 or 2025, and only your host can say which. The first of those to lose support is Windows Server 2016, on January 12, 2027.
PHP sites, WordPress included, depend on the PHP version. Most hosts can switch a site to a newer version from their control panel, though old plugins sometimes need updating first.
For the background on older Microsoft sites, read why old Microsoft websites stay put until support runs out.
Common questions
Is it okay to check a site that isn't mine?
Yes. The check sees only what any visitor's browser sees, and it makes one visit to one page.
Why does it say it couldn't tell?
Many sites hide their software, often behind a service like Cloudflare. That is normal. Ask whoever hosts the site. The result gives you the questions to send them.
Do you keep the addresses I check?
No. We keep a count of how many checks run and what kind of sites they find, and nothing else.
My site runs on Classic ASP. What now?
Nothing changes today. Find out which Windows Server version it runs on and when that version's support ends, then put the date on your calendar. Our article on why old Microsoft websites stay put walks through the dates.