Which AI builder made this website? A fingerprint guide to Bolt, v0, Base44, Replit and more
Every AI app builder leaves its own marks. This reference shows the domains, scripts, headers and badges that name the builder behind a site.
Once you suspect a site was vibe coded, the next question is which AI builder made this website. The answer matters more than it sounds: it tells you where to report abuse, what the site is likely built on, and how much weight to give the evidence. The good news is that builders are easier to tell apart than to detect in the first place, because each one stamps its own marks.
This guide is a reference. For the general method, start with how to tell if a website was made with AI. For what each kind of evidence is worth and the full rule list for 22 builders, see how to tell if a website was built with an AI builder.
Quick reference
| Builder | Hosting domains | In the source or headers |
|---|---|---|
| Lovable | lovable.app, lovableproject.com, gptengineer.app | gptengineer.js, data-lov-id, /lovable-uploads/ |
| Bolt | bolt.host, bolt.new | x-powered-by: Bolt.new, bolt.new/badge.js, Made with Bolt |
| v0 | vusercontent.net, v0.app, v0.build | Generator tag naming v0, Built with v0, v0 Apptitle |
| Base44 | base44.app | app.base44.com calls, Base44app title tag |
| Replit | replit.app, replit.dev, repl.co | replit-cluster header, Replit badge |
| Manus | manus.space | Made with Manus |
| Emergent | emergent.host, emergentagent.com | assets.emergent.sh, Emergent badge |
| Gamma | gamma.site | assets.gammahosted.com, x-super-powered-by header |
| Figma Make | figma.site | Figma-hosted assets |
| Dyad | Self-hosted | data-dyad-id, Made with Dyad |
| Hostinger Horizons | Hostinger | x-generator: Hostinger Horizons |
| Google AI Studio | Varies | aistudiocdn.com import map, My Google AI Studio Apptitle |
Kitsuvo also recognises Mocha, Rocket, Macaly, Same, Leap, Magic Patterns, Durable and B12 by their hosting and asset domains; see the guide to newer AI builders. For the big three side by side, read Lovable vs Bolt vs v0.
Bolt
Bolt, from StackBlitz, runs projects in the browser and publishes them to *.bolt.host. Its most reliable fingerprint is a response header: Bolt's hosting sends x-powered-by: Bolt.new. To see it, open the developer tools (F12), choose Network, reload, and click the first request.
Free Bolt sites also carry a badge, loaded from bolt.new/badge.js, with text like Made with Bolt
or Built with Bolt
and a referral link containing bolt.new/?rid. More in how to tell if a website was built with Bolt.
v0
v0 is Vercel's AI builder. Previews and published apps live on *.vusercontent.net and *.v0.app. Projects often keep a <meta name="generator" content="v0.app"> tag or a description such as Created with v0
, and the default tab title is v0 App
.
Because v0 deploys to Vercel, many v0 sites end up on *.vercel.app or a custom domain. Vercel itself hosts a huge amount of hand-built software, so a Vercel address alone means very little. More in how to tell if a website was made with v0.
Base44
Base44, owned by Wix, publishes apps on *.base44.app. On custom domains, the giveaway is the app talking to its backend: look in the Network tab for requests to app.base44.com. Base44 also sets a default apple-mobile-web-app-title of Base44
. More in how to tell if a website was built with Base44.
Replit
Replit is different from the others. It has an AI agent that builds whole apps, but it is also a place where people have written code by hand for years. A *.replit.app address therefore says "hosted on Replit", not necessarily "built by AI". Kitsuvo gives Replit hosting less weight for that reason and looks for other signs before calling it. More in how to tell if a website was built with Replit.
Telling Lovable, Bolt and v0 apart by look
You mostly can't. All three generate React with Tailwind CSS and shadcn/ui, so a gradient hero with three feature cards could come from any of them, or from a person. A few loose tendencies exist, such as Lovable's fondness for Sonner toasts and v0's close match to Vercel's own templates, but they are hints at best.
If the only evidence is visual, the fair conclusion is "possibly vibe coded", with no builder named. Naming a builder needs a fingerprint.
Why naming the builder helps
- Reporting abuse. If a builder-hosted page is impersonating a brand, the builder can take it down. Knowing it is Lovable or Bolt tells you whom to report it to.
- Calibrating trust. A hosting fingerprint is near-certain. A style match is a guess. Knowing which you have keeps you fair to the site's owner.
- Context. A Gamma site is usually a presentation-style page; a Base44 app usually has a database and sign-in behind it.
Kitsuvo runs all of these checks on every page you open and puts the builder's name next to the score in the address bar, along with the evidence it matched. For a deeper look at one builder, see how to tell if a website was built with Lovable.
Questions people ask
How do I know if a website was made with Bolt?
Check whether the address ends in bolt.host, look for a Made with Bolt
badge, and in the developer tools Network tab check for the response header x-powered-by: Bolt.new.
How do I know if a site was made with v0?
v0 sites are often on vusercontent.net or v0.app. On other domains, look for a generator meta tag or description that mentions v0, or the default title v0 App
.
Can one site show fingerprints from two builders?
Yes. People sometimes start in one builder and finish in another, or copy components between projects. Kitsuvo reports the builder with the strongest evidence and lists every signal it found.