Web & Mobile Performance

Flexible Caching

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Event-driven content

Much of the content served on websites and mobile apps is neither static nor fully dynamic. News headlines, stock prices, weather, and inventory remain static for some period of time and then change unpredictably. Traditional CDNs call this dynamic content and treat it as uncacheable, since they lack the ability to instantly purge stale content.

We consider this type of content “event-driven,” and we can cache it because it can be purged instantly. Our Instant Purge feature allows you to cache and invalidate content almost as soon as it’s updated on your origin server — within 150 milliseconds on average across our global network.

API content

The same technology that we use to cache event-driven content also allows us to cache APIs, which typically change quickly and unpredictably. Whether your app offers real-time weather or the latest sports scores, you need to be able to quickly replace outdated content with the most up-to-date information.

Static content

In addition to caching event-driven content, Fastly excels at caching static content, whether it’s an image, JavaScript, CSS, or larger objects like downloads, music, video, or PDF files. Our state-of-the-art network allows us to cache more objects for longer and retrieve them faster. You’ll achieve better cache hit ratios, translating to quicker response times and downloads for your web and mobile users.