Offline Mode

With Offline Mode, features that do not require a connection to WordPress.com servers can be activated on a localhost WordPress installation for testing.

Note: This is specifically for offline, local development sites. If you have an online, staging site, you’ll want to follow the Staging Sites guide instead.

You can turn on Offline Mode by adding define( 'JETPACK_DEV_DEBUG', true ); to your wp-config.php file. Make sure you add it before the /* That's all, stop editing! Happy blogging. */ line.

Offline mode automatically gets enabled if you don’t have a period in your site’s hostname, i.e. localhost. If you use a different URL, such as mycooltestsite.local, then you will need to define the JETPACK_DEV_DEBUG constant.

You can also enable Jetpack’s Offline mode through a plugin, thanks to the jetpack_development_mode filter:

add_filter( 'jetpack_offline_mode', '__return_true' );

While in Offline Mode, some features will not be available at all, as they require WordPress.com for all functionality—Related Posts and Jetpack Social, for example. Other features will have reduced functionality to give developers a good-faith representation of the feature. For example, Tiled Galleries requires the WordPress.com image CDN; however, in Offline Mode, Jetpack provides a fallback so developers can have a similar experience during development and testing.