Plugins

JSON Data Feed can be used to supplement a WordPress blog's normal XML feeds with a JSON feed. Install it, activate it, and you're done.

Adds a feed based on the jsonfeed.org standard that one can subscribe to or parse.

Revieve a JSON response from any post, page or archive by adding ?json to the url.

Import and Export WordPress Options to/from JSON with filters.

Register a post type for managing arbitrary JSON configurations with an easy WYSIWYG editor.

JSONPress - Allows you to request WordPress site via JSON/JSONP output.

Fetches data from a Json file and displays it via shortcode, you can use the key parameter to filter the data

Force WP REST API endpoints to only be served over HTTPS.

Enable subscriptions to posts, pages, and custom post types. Users can securely subscribe via simple API routes to created/updated/deleted content.

Makes iframes responsive using some lightweight JavaScript.