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Is This Website Built With Fastly?

Paste any URL below. Our scanner checks 2 Fastly-specific fingerprints — scripts, CDN domains, HTML attributes, and HTTP headers — and returns a confidence score instantly.

How to Tell if a Website Uses Fastly

Identifying whether a website was built with Fastly used to require technical expertise — inspecting source code, tracing network requests in DevTools, and knowing which patterns to look for. Our free scanner automates all of that: it fetches the page, analyzes 2 Fastly-specific signals, and returns a verdict with a confidence score.

You might want to detect Fastly for competitive research, due diligence before acquiring a site, or simple curiosity. Whatever the reason, this page covers every method — automated and manual.

What is Fastly?

Fastly is a high-performance edge cloud platform and content delivery network used primarily by enterprises, media companies, and high-traffic web applications that require low-latency content delivery, real-time streaming, and programmable infrastructure at scale. The platform is widely adopted by technology companies, news publishers, and e-commerce operators that demand granular control over caching and request routing at the network edge. AIWebsiteDetector.com identifies Fastly deployments by analyzing 2 distinct HTTP response headers that Fastly injects into served traffic, providing reliable, server-side signals that remain consistent across the wide variety of site types and configurations built on the platform. These header-based signals make Fastly particularly straightforward to detect programmatically, as they appear regardless of front-end framework or CMS in use, meaning the underlying CDN layer is exposed even when the application stack is otherwise obscured. Fastly operates on a usage-based pricing model with no upfront commitments, positioning it as a premium infrastructure choice that distinguishes it from shared or budget hosting environments — a characteristic that often correlates with high-traffic, performance-critical deployments in detection results.

It is primarily used for business websites, portfolios, landing pages, and personal sites without coding knowledge.

Visit Fastly official website

Signs a Website Is Built With Fastly

Our detection engine checks 2 unique Fastly fingerprints. Here are the most reliable signals:

High Confidence

HTTP Response Headers

Fastly-hosted sites respond with specific HTTP headers that identify the platform or infrastructure. These are visible in DevTools → Network tab.

x-fastly-request-idx-served-by

How to Manually Detect Fastly Websites

Method 1 — View Page Source

  1. Open the website in your browser
  2. Press Ctrl+U (Windows) or Cmd+Option+U (Mac)
  3. Search (Ctrl+F) for fastly or fastly
  4. If found in script src, class names, or meta tags — it's likely Fastly

Method 2 — Browser DevTools Network Tab

  1. Press F12 to open DevTools
  2. Click the Network tab and reload the page
  3. Filter by fastly in the search box
  4. If you see requests to Fastly-specific domains, it's confirmed
Faster: Skip the manual steps — paste the URL into our scanner above and we check all 2 signals in seconds.

How Our Fastly Detector Works

When you submit a URL, our engine fetches the page from its server — just like a browser would — then analyzes the response across 2 Fastly-specific fingerprints:

Script analysis

We scan all loaded JavaScript files for known CDN paths and runtime names

CDN domain matching

We cross-reference every asset request against known platform CDNs

HTML pattern scanning

We search the DOM for platform-specific class names and data attributes

Header inspection

We read HTTP response headers that identify the server or platform

Meta tag extraction

We check generator and other meta tags in the document head

Confidence scoring

We weight each matched signal and normalize to a 0–99% score

How to Build a Similar Website With Fastly

Sign up at https://www.fastly.com, pick a template, customize it with the drag-and-drop editor, add your content, and publish. Most website builders offer free plans to get started.

Other popular website builders include Wix, Squarespace, Webflow, Carrd, and Showit.

Get started with Fastly

Frequently Asked Questions

How can I tell if a website was built with Fastly?

The most reliable ways to detect Fastly are: (1) open DevTools → Network tab and look for requests to Fastly-specific CDN domains, (2) view page source and search for Fastly-specific class names or data attributes, (3) use our free scanner — we check 2 detection signals automatically and return a confidence score.

Is your Fastly detector free?

Yes, completely free. Paste any URL into our scanner and we'll analyze it for Fastly fingerprints immediately. No account required, no limits on scans.

How accurate is the Fastly detection?

We check 2 unique Fastly fingerprint signals across HTML, JavaScript, CDN domains, meta tags, and HTTP headers. Our confidence score reflects how many signals matched — a score above 70% is a strong indicator. We cap accuracy at 99% to reflect that all fingerprint-based detection is probabilistic.

Can Fastly sites be detected if they use a custom domain?

Yes. Custom domains don't hide the underlying platform. The JavaScript files, CDN requests, HTML attributes, and server headers all remain identifiable regardless of the domain name used. Our scanner fetches the page directly and analyzes its technical composition.

What should I do after detecting a Fastly website?

If you want to build something similar, visit https://www.fastly.com to learn more or sign up. If you're doing competitive research, our scan result also shows the full technology stack — including hosting platform, domain age, and other detected technologies. You can share the result link with your team.