What Is Ruby?
FrameworkRuby powers Ruby on Rails and applications such as Discourse and Redmine. Detection relies on the banners of Ruby application servers and on a detected Rails site.
Detect Ruby on any website:
Why Ruby Matters
Framework choice shapes hiring, tooling, deploy targets, and long-term maintenance. If you've inherited a Ruby codebase, are comparing it against alternatives, or are trying to recreate a site that uses it, knowing how Ruby leaves fingerprints in production HTML is the fastest way to ground-truth the stack without opening the repo. We've fingerprinted Ruby on 11 live sites in our database, so the answers here are grounded in real scan data — not marketing copy.
Does Ruby Mean a Site Was Built With AI?
Ruby alone is not an AI signal.
A backend framework is standard web tooling used by hand-coding developers and AI tools alike. It becomes weak supporting context only in combination with other evidence — for example a shadcn/ui + Supabase + Vite bundle that matches a known AI-builder export — and never counts as proof on its own.
How this feeds the score: builder fingerprints, bundle artifacts and AI-tool traces are weighed separately from stack context like frameworks, libraries and hosting. The full breakdown is on How scores work.
How Websites Using Ruby Work
- Server banners such as Phusion Passenger, Puma, Unicorn or Thin
- X-Powered-By naming Phusion Passenger or Ruby
- Implied by a detected Ruby on Rails application
- A stack fact only — neutral on authorship
Best Practices When Working With Ruby
Based on patterns in our scan dataset and the detection evidence tiers.
- →Start by running a Ruby detection scan on any URL you're evaluating — the 80+ signal engine returns a confidence score plus the exact markers it matched, which beats reading view-source by hand.
- →Cross-check the result against the full detection evidence in /how-scores-work — confidence tiers tell you whether a match is strong (headers + scripts) or circumstantial (a single HTML pattern).
- →Use Ruby detection results alongside the hosting + CDN signals on the same scan report — the framework only tells half the deployment story.
How we detect Ruby — see our methodology: AI Influence Score calculation, evidence tiers, and fingerprint signal types.
How Our Detector Identifies Ruby
Our scanner analyzes multiple layers of a website's technical fingerprint to detect Ruby usage.
- HTTP response headers: server containing "Phusion Passenger|Puma|Unicorn|Thin|WEBrick|Thruster"; x-powered-by containing "Phusion Passenger|Ruby" (high-confidence tier)
- Signal weights for Ruby: 85 points per high-tier match, 55 per medium, 25 per low — a site needs 60+ points before Ruby is reported.
Websites Built With Ruby
Real sites detected by our scanner
What Ruby Sites Usually Run Alongside
Technologies detected on the same domains as Ruby in our most recent scans. Counts are unique domains, not page views.
Frequently Asked Questions About Ruby
What is Ruby?+
Ruby powers Ruby on Rails and applications such as Discourse and Redmine. Detection relies on the banners of Ruby application servers and on a detected Rails site.
Does Ruby mean a website was built with AI?+
Ruby alone is not an AI signal. A backend framework is standard web tooling used by hand-coding developers and AI tools alike. It becomes weak supporting context only in combination with other evidence — for example a shadcn/ui + Supabase + Vite bundle that matches a known AI-builder export — and never counts as proof on its own.
Why does Ruby matter?+
Framework choice shapes hiring, tooling, deploy targets, and long-term maintenance. If you've inherited a Ruby codebase, are comparing it against alternatives, or are trying to recreate a site that uses it, knowing how Ruby leaves fingerprints in production HTML is the fastest way to ground-truth the stack without opening the repo. We've fingerprinted Ruby on 11 live sites in our database, so the answers here are grounded in real scan data — not marketing copy.
How do we detect Ruby?+
Our scanner checks for these signals: HTTP response headers: server containing "Phusion Passenger|Puma|Unicorn|Thin|WEBrick|Thruster"; x-powered-by containing "Phusion Passenger|Ruby" (high-confidence tier); Signal weights for Ruby: 85 points per high-tier match, 55 per medium, 25 per low — a site needs 60+ points before Ruby is reported.. Each match contributes to a confidence score, and the full evidence tiers are documented at /how-scores-work.
How many websites using Ruby are in the database?+
We've fingerprinted 11+ live sites built with Ruby across our scan dataset. The list refreshes as new scans come in.
What are the typical characteristics of a Ruby website?+
Server banners such as Phusion Passenger, Puma, Unicorn or Thin. X-Powered-By naming Phusion Passenger or Ruby. Implied by a detected Ruby on Rails application. A stack fact only — neutral on authorship
Related Tools & Technologies
Other frameworks we detect
Ready to put Ruby detection to work?
You now know what Ruby is, why it matters, how to spot it, and where the detection signals come from. The next step is using that knowledge on a real URL — yours, a competitor's, or a prospect's.