React Detector
Paste any URL and instantly see whether the site is built with React — with the matched evidence.
We do not store the URL you audit. Want the full audit (performance / images / SEO / accessibility + real-browser speed test)? → run the full audit
Why check this
Confirm the platform first: Framework decides what can be changed and whether it is worth it.
What this is
React is a component UI library behind many marketing sites and web apps — sometimes via Next, sometimes via a custom bundle. Confirming fingerprints such as `data-reactroot` or `react-dom` shows whether hydration or third-party scripts own the main thread. A JSX tutorial alone is not a runtime hit.
How to tell from a public page
- [React] Markup includes `data-reactroot` or modern root attributes.
- [React] Scripts reference `react-dom` or a production.min build.
- [React] Runtime leaves internals such as `_reactListening`.
- [React] Error-boundary or development-build comments appear near source maps.
How to read the result
Confirm when runtime DOM or script fingerprints reproduce; an article teaching components remains only suspected. Absence can mean compilation to another runtime or a Preact compat layer. Documentation sample HTML is a frequent soft match. After a hit, separate the library itself from any meta-framework above it.
What to do next
Shrink unnecessary client trees, defer non-critical components, and distinguish whether the stack is actually Next — open Next.js detector. Full vitals return via run the full performance / images / SEO / accessibility audit on the home page. Separate library fingerprints from meta-framework clues in the ticket.
Related detectors
FAQ
How is React detected?
From structural signatures in the public HTML and response headers (domains, paths, attributes, scripts). Every verdict lists how many times each pattern matched — nothing is guessed.
Can the result be wrong?
If only a bare brand keyword matches without structural evidence, we label it \u201clikely\u201d instead of \u201cconfirmed\u201d — we would rather under-report than cry wolf.
Do you save the URLs I check?
No. The audit runs inside the request and the URL you paste is not written to storage. There are no third-party tracking scripts on the page either, so no log of who checked what exists. Copy the result yourself if you want a record.
Can a website hide what it is built with?
Partly, but rarely completely. The HTML sent to your browser, the response headers, script paths and asset structure have to be exposed to work, so there is always something readable. Server-side code, build config and private APIs stay invisible. That is why this tool reports the evidence it found rather than claiming a full picture. No match does not mean the technology is absent.
Optimization help is available
Tell me your URL and what you want fixed — you get a clear scope, price and timeline.
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