Managing app performance

Amplify's default hosting architecture optimizes the balance between hosting performance and deployment availability. For most customers, we recommend that you use the default architecture.

If you require finer control over an app's performance, you can manually set the HTTP Cache-Control header to optimize for hosting performance by keeping content cached at the content delivery network (CDN) edge for a longer interval.

Using headers to control cache duration

HTTP Cache-Control header's max-age and s-maxage directives affect the content caching duration for your app. The max-age directive tells the browser how long (in seconds) that you want content to remain in the cache before it is refreshed from the origin server. The s-maxage directive overrides max-age and lets you specify how long (in seconds) that you want content to remain at the CDN edge before it is refreshed from the origin server.

Apps hosted with Amplify honor the Cache-Control headers that are sent by the origin, unless you override them with custom headers that you define. Amplify only applies Cache-Control custom headers for successful responses with a 200 OK status code. This prevents error responses from being cached and served to other users that make the same request.

You can manually adjust the s-maxage directive to have more control over the performance and deployment availability of your app. For example, to increase the length of time that your content stays cached at the edge, you can manually increase the time to live (TTL) by updating s-maxage to a value longer than the default 600 seconds (10 minutes).

You can define custom headers for an app in the Custom headers section of the Amplify console. For an example of the YAML format, see Custom Cache-Control headers.

Setting the Cache-Control header to increase app performance

Use the following procedure to set the s-maxage directive to keep content cached at the CDN edge for 24 hours.