---
title: expireTime
description: Customize stale-while-revalidate expire time for ISR enabled pages.
---

{/* The content of this doc is shared between the app and pages router. You can use the `<PagesOnly>Content</PagesOnly>` component to add content that is specific to the Pages Router. Any shared content should not be wrapped in a component. */}

You can specify a custom `stale-while-revalidate` expire time for CDNs to consume in the `Cache-Control` header for ISR enabled pages.

Open `next.config.js` and add the `expireTime` config:

```js filename="next.config.js"
module.exports = {
  // one hour in seconds
  expireTime: 3600,
}
```

Now when sending the `Cache-Control` header the expire time will be calculated depending on the specific revalidate period.

For example, if you have a revalidate of 15 minutes on a path and the expire time is one hour the generated `Cache-Control` header will be `s-maxage=900, stale-while-revalidate=2700` so that it can stay stale for 15 minutes less than the configured expire time.