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.
Detect Fastly Websites — Free Tool
Enter any URL to check if it was built with Fastly. Instant results, no account required.
How we detect Fastly — see our methodology: AI Influence Score calculation, evidence tiers, and fingerprint signal types.
How to Detect Fastly Websites
HTTP Headers
2 patterns
1. Check the Page Source
Open the website in your browser, right-click, and select "View Page Source". Search for fastly-specific patterns in the HTML.
4. Use AI Website Detector (Easiest)
Our automated scanner checks all these signals at once and gives you an instant confidence score. Just enter any URL above.
Frequently Asked Questions
Is this website built with Fastly?
You can detect if any website was built with Fastly by using our free scanner above. Just enter the URL and we'll analyze HTML patterns, JavaScript files, CDN domains, and HTTP headers to determine if Fastly was used — with a confidence score.
How to detect if a website was built with Fastly?
There are several ways to detect Fastly: (1) View the page source and look for Fastly-specific class names or script URLs, (2) Check the Network tab in DevTools for requests to Fastly CDN domains, (3) Use our free tool — we check 2 detection signals automatically.
What websites are built with Fastly?
Fastly is used by thousands of websites worldwide. Our scanner has detected many Fastly-built sites across different industries. You can scan any URL to check if it uses Fastly.
How accurate is the Fastly detection?
Our Fastly detection engine checks 2 unique fingerprint signals, achieving high confidence results. We score each match and return a confidence percentage so you know how certain the detection is.
About Fastly
Fastly is a leading cdn used by thousands of businesses and developers worldwide. Our detection engine can identify Fastly-built websites with high confidence by analyzing multiple technical signals.
Whether you're a developer doing competitive research, a designer looking for inspiration, or just curious about how a website was built — AI Website Detector gives you instant, accurate detection.
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Detection Info
- Category
- CDN
- Signals Used
- 2 patterns
- Accuracy
- High
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