APL File Formats and Encodings

The Alexa Presentation Language (APL) encodes and transmits data in the JSON data serialization format (ECMA-404). Follow these guidelines when working with the JSON serialization and APL presentation.


APL supports Unicode, and skill developers can display text from almost any language on Alexa-enabled devices with screens.

JSON object name conventions

A JSON object is an unordered set of name/value pairs. Each name is a string. APL observes the following conventions for the build-in name strings:

  • Name strings contain only the characters [a-zA-Z].
  • Name strings start with a lowercase character [a-z].
  • Name strings follow the camel-case convention when they consist of two or more words, such as "alignSelf", "paddingLeft", "fontSize".

Reserved object names

APL reserves the use of JSON names that start with characters other than [a-zA-Z]. APL runtimes ignore all JSON names starting with other characters.


All APL properties and enumerated values are case-sensitive.

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Last updated: Nov 28, 2023