How do I tell if a website is built with Webflow?

Open the page source (View Source) and look at the tag — Webflow adds data-wf-page and data-wf-site attributes there, which is the clearest single tell. Also search the source for a generator meta tag reading Webflow and for a webflow.js script. In the Network tab, assets loading from assets-global.website-files.com confirm it. Any one of these is strong; together they are conclusive.

What is the data-wf-page attribute?

data-wf-page and data-wf-site are attributes Webflow places on the root element of every page it publishes, holding internal page and site identifiers. They are part of how the Webflow runtime works and are present on virtually every Webflow site, which makes them the most reliable detection signal. You will see them immediately at the top of the page source, before you read anything else.

What is a .webflow.io domain?

When you build a site in Webflow but have not yet connected a custom domain, Webflow hosts it on a free staging subdomain like your-project.webflow.io. Seeing a site on a *.webflow.io address is an instant confirmation that it is built with Webflow. Once a custom domain is attached the .webflow.io URL still works as a staging copy, so it can be a useful tell even for live sites.

What kind of sites is Webflow used for?

Webflow is a visual, no-code web design platform aimed at designers, agencies and marketing teams who want pixel-level control over layout without writing front-end code. It is popular for marketing sites, portfolios, landing pages and brochure sites, and includes a CMS for blogs and collections. Confirming Webflow therefore tells you the front end was designed visually rather than hand-coded, which shapes how the site can be edited and extended.

Is Webflow detection reliable?

Yes, very. Webflow's data-wf-page and data-wf-site attributes, its generator tag, webflow.js and its asset domains are all distinctive and present on the large majority of Webflow sites, so detection is among the more dependable in the website-builder category. The main edge cases are sites that have exported their Webflow code and self-hosted it (which can strip the runtime tells) or heavily customised builds, but even those usually retain recognisable asset references.

How to Tell if a Website Is Built with Webflow

Wondering whether a slick marketing site was built with Webflow? It is one of the easier platforms to confirm, because Webflow stamps its pages with unmistakable fingerprints. The clearest is right at the top of the page source: the data-wf-page and data-wf-site attributes on the <html> element. Add a generator meta tag reading "Webflow", a webflow.js script, and assets loading from assets-global.website-files.com, and you have a conclusive identification in under a minute. This guide covers every signal, what Webflow is and who uses it, and the handful of edge cases where detection gets trickier.

This is a focused companion to how to tell what website builder a site uses; here we concentrate on Webflow specifically.

What is Webflow, and who uses it?

Webflow is a visual, no-code web design platform. It lets designers and agencies build production websites by arranging elements on a canvas with pixel-level control over layout, typography and interactions, while Webflow generates the underlying HTML, CSS and JavaScript. It includes a hosting layer and a CMS for blogs, collections and dynamic content. The audience skews toward designers, agencies, freelancers and marketing teams who want fine creative control without hand-coding the front end — so Webflow is especially common for marketing sites, landing pages, portfolios and brochure sites, and increasingly for content-driven sites via its CMS. Confirming that a site is built with Webflow therefore tells you something real about how it was made and how it can be edited: visually, by a designer, rather than in a code editor by an engineer.

The clearest tell: data-wf-page and data-wf-site

The single most reliable Webflow signal lives on the root element. Open View Source (Ctrl+U / Cmd+Option+U) and look at the opening <html> tag. On a Webflow site it carries two attributes:

<html data-wf-page="65f2..." data-wf-site="64ab..." lang="en">

These hold Webflow's internal page and site identifiers, and they are part of how the Webflow runtime operates, so they appear on virtually every published Webflow site. Because they sit at the very top of the document, you do not even need to scroll — they are the first thing you see. This is the gold-standard tell: when both data-wf-page and data-wf-site are present, you are almost certainly looking at Webflow.

The generator tag and webflow.js

Two more signals confirm it quickly. First, search the source for the generator meta tag, which Webflow sets explicitly:

<meta name="generator" content="Webflow" />

Second, look for the webflow.js script (often named webflow.<hash>.js and loaded near the end of the body). This is Webflow's front-end runtime, responsible for interactions and animations, and its presence is a strong corroboration. Together with the data-wf-* attributes, these two signals form a textbook three-point confirmation.

Asset domains in the Network tab

Webflow serves images, CSS and other assets from signature domains that are easy to spot in DevTools. Open the Network tab (F12 → Network), reload, and watch where resources load from:

assets-global.website-files.com — Webflow's primary global asset CDN, hosting images, CSS and uploaded media. This is the most common asset tell.
uploads-ssl.webflow.com — an older Webflow asset domain still seen on many sites.
d3e54v103j8qbb.cloudfront.net and similar — Webflow's CDN endpoints for shared assets like its jQuery copy.

Seeing your target site pull images and stylesheets from website-files.com is a clear platform fingerprint, and it survives even when you only have the rendered page rather than clean source.

A table of Webflow signals

The signals are easiest to use side by side. This summarises where each lives and how strong it is.

Signal	Where to find it	Strength
`data-wf-page` / `data-wf-site` on `<html>`	View Source, top of document	Very strong
Generator meta tag "Webflow"	View Source (`<head>`)	Very strong
`webflow.js` runtime script	View Source / Network tab	Strong
`assets-global.website-files.com` assets	Network tab	Strong
`uploads-ssl.webflow.com` assets	Network tab	Strong
`*.webflow.io` domain	the address bar	Conclusive (staging)
`w-` prefixed CSS classes (`w-container`, `w-nav`)	Elements panel	Supporting

Any one of the "very strong" or "conclusive" rows settles it. The supporting w- class prefix — Webflow names many of its built-in components with a w- prefix, like w-container, w-nav and w-button — is a nice extra confirmation once you have a primary signal.

The .webflow.io staging giveaway

There is one signal that needs no inspection at all: the domain. Every Webflow project gets a free staging subdomain in the form your-project.webflow.io. If the site you are looking at is on a *.webflow.io address, it is unquestionably built with Webflow — that domain is issued by Webflow and used nowhere else. Even after a site connects a custom domain, the .webflow.io staging URL typically keeps working as a preview copy. So if you can find or guess the staging URL, loading it is an instant, zero-effort confirmation. This is the equivalent of the *.webflow.io tell that other builders have (Wix's *.wixsite.com, for example), and it is one of the fastest checks in the whole builder category.

Methods, step by step

Putting the tools together, the practical sequence is short:

View Source and read the <html> tag for data-wf-page / data-wf-site.
Search the source (Ctrl+F) for generator and for webflow.
Open the Network tab, reload, and look for website-files.com asset requests.
Inspect an element and scan for w- prefixed classes.
Check the address for a .webflow.io domain, and try the staging URL if you can find it.

Most of the time the first step alone answers the question; the rest are corroboration for a confident, defensible read.

Tools that detect Webflow automatically

If you prefer one click, the usual detectors all recognise Webflow:

Wappalyzer — the browser extension reports "Webflow" under CMS or website builders for the current page.
BuiltWith — profiles the domain and lists Webflow among its technologies, with history on paid tiers.
View Source and DevTools — the manual tools behind the automated answer, and how you verify it.
StackOptic — a full website audit that names the builder alongside hosting, performance, SEO and accessibility in one pass.

As always, these tools read the same data-wf-* attributes and asset domains you can read yourself, so a quick manual confirmation is worth it when the answer matters.

The edge cases

Webflow detection is reliable, but two situations can muddy it. First, Webflow lets you export the generated code and host it elsewhere; an exported, self-hosted site can lose the data-wf-* runtime attributes and the website-files.com asset domain, leaving only fainter traces like the w- class prefixes in the CSS. Second, a heavily customised build with extensive custom code embedded can bury the default tells, though the core attributes usually survive because they are part of how published Webflow pages are structured. In both cases, the w- class naming convention in the stylesheet is often the surviving clue. When you suspect Webflow but the obvious signals are absent, scanning the CSS for w-container, w-nav and friends is the fallback. This is the same principle that runs through all platform detection — see how to find out what a website is built with for the general approach of stacking multiple signals.

Spotting the Webflow CMS and e-commerce

Webflow is not only a static-site designer; it includes a CMS for dynamic content and an e-commerce layer for stores, and both leave additional tells once you have confirmed the platform. A Webflow site using the CMS renders Collection content — blog posts, team members, case studies — into templated pages, and you will often see Webflow's w-dyn-list, w-dyn-items and w-dyn-item classes wrapping repeated content in the markup. These dynamic-list classes are a reliable sign that the page is driven by Webflow Collections rather than hand-placed elements. A Webflow e-commerce site adds cart and checkout markup and product Collection pages on top of the same data-wf-* foundation, with the checkout running on Webflow's commerce infrastructure. So, as with the other builders, detection is layered: confirm Webflow from the data-wf-page attribute and asset domains first, then look for the w-dyn-* classes to tell whether the site is using the CMS, and for cart markup to tell whether it sells. The underlying platform fingerprints never change; the CMS and commerce markers simply sit on top.

What you can and cannot change on a Webflow site

Confirming Webflow also clarifies what is editable and what is fixed, which matters for anyone scoping work on the site. Because Webflow generates the front-end code from a visual designer, the layout, styling, interactions and CMS content are all editable inside Webflow's designer and editor — often with a great deal of flexibility, since Webflow exposes the underlying CSS box model rather than hiding it behind rigid templates. What you generally cannot do is treat the site like a hand-coded project: you are working within Webflow's structure, its class system and its hosting (unless the code has been exported and self-hosted, which then forgoes the CMS and editor entirely). For performance work, the same logic applies as on other builders: you control image optimisation, the weight of custom code and embeds you add, and the structure of your content, while the platform manages hosting and serves its own runtime. Knowing the site is Webflow tells you precisely where those boundaries sit, so you can scope a redesign, a content update or an optimisation pass without surprises.

Webflow versus other builders

It helps to know how Webflow sits relative to its peers, because telling builders apart is a common task. Webflow's design-tool depth and pixel-level control distinguish it from the more template-driven Wix and Squarespace, which trade some flexibility for ease — and which have their own distinct fingerprints, covered in how to tell if a website is built with Wix or Squarespace. Where Wix and Squarespace are aimed squarely at non-technical users, Webflow targets designers who think in terms of layout, classes and interactions, which is why its output carries that w- class system and its editor resembles a design application. Recognising these differences means that even before you read the source, the feel of a site — highly custom and design-led versus templated — can hint at which builder to check for first.

What confirming Webflow tells you

Once you know a site is Webflow, several things follow. The front end was designed visually, not hand-coded, so editing it means working in Webflow's designer, not a code repository. The site is likely hosted by Webflow (unless exported), with its performance and reliability tied to that platform. Content is probably managed through Webflow's CMS if the site is content-driven. And the build was most likely done by a designer or agency comfortable in visual tools. For competitive research, design inspiration or scoping a takeover, that is a lot of useful context from a single confirmed platform — and it pairs naturally with reading the site's visual choices in how to find what fonts and colours a website uses.

The fast, reliable workflow

View Source and check the <html> tag for data-wf-page and data-wf-site.
Search for the generator tag "Webflow" and a webflow.js script.
Network tab: confirm assets from assets-global.website-files.com.
Check the domain for .webflow.io and try the staging URL.
Look for w- classes as a fallback on exported or customised builds.
Cross-check two signals for a confident, defensible answer.

Go deeper

The general question: how to tell what website builder a site uses.
The other big builders: how to tell if a website is built with Wix or Squarespace.
The complete method: how to find out what a website is built with.
Read the design too: how to find what fonts and colours a website uses.

Want the builder, hosting and full stack identified in one pass? Analyse any website with StackOptic — one report, free, no sign-up.