Enabling Partial Prerendering (PPR) for an entire application is ideally, the goal for teams wanting to test out the feature or adopt it in their applications to get ready for when it becomes the default rendering pattern. For large applications, with many routes the new behaviours of old API's may prove a difficult pill to swallow all at once.

This aims to enable incremental adoption of PPR for pages and routes that want to support it in a similar way to how existing segment-level configurations. Segments can now add:

export const experimental_ppr = true

To enable PPR for that segment and those descending segments. Any subset of those routes that have it enabled can add:

export const experimental_ppr = false

To disable PPR for that segment and those descending segments. To use this new option, the experimental.ppr configuration in next.config.js must be set to "incremental":

// next.config.js
module.exports = {
  experimental: {
    ppr: "incremental",
  },
} 

If a segment does not export a experimental_ppr boolean, it is inferred from it's parent. If no parent has it defined, it's default value is false and therefore disabled.

Once all your segments have PPR enabled via this config, it would be considered safe for teams to set their experimental.ppr value in the next.config.js to true, enabling it for the entire app and for all future routes.

Aside

I also took the liberty to rename isPPR and supportsPPR to be the clearer isAppPPREnabled and isRoutePPREnabled.