JSON Schema

Hackolade is a visual editor for JSON Schema for non-programmers.  It is ideal to perform the upfront schema design of any type of JSON document   Since v5 of Hackolade, the latest JSON Schema specifications are supported:

- draft-04

- draft-06

- draft-07

- 2019-09


Hackolade was specially adapted to support the data modeling of JSON files.



JSON (JavaScript Object Notation) is a lightweight data-interchange format. It is easy for humans to read and write. It is easy for machines to parse and generate.  It is based on a subset of the JavaScript Programming Language.  JSON is a text format that is completely language independent but uses conventions that are familiar to programmers of the C-family of languages.  These properties make JSON an ideal data-interchange language.  JSON is built on two structures:

  • A collection of name/value pairs. In various languages, this is realized as an object, record, struct, dictionary, hash table, keyed list, or associative array.
  • An ordered list of values. In most languages, this is realized as an array, vector, list, or sequence.





With version 5 of Hackolade, support was introduced for the conditional application of subschemas.  The if, then and else keywords allow the application of a subschema based on the outcome of another schema:





You will find more information about JSON Schema on the website.  



Hackolade dynamically generates JSON Schema for the structure created with the application, and can be pre-viewed with a variety of options, as further described here. The JSON Schema can also be exported to the file system via the menu Tools > Forward-Engineering, or via the Command-Line Interface.





The JSON Schema can also be exported to a Confluent Schema Registry instance:





Hackolade can reverse-engineer of course JSON Schema from different drafts, but also infer the schema from JSON, YAML or NDJSON documents.  It can lso convert DDLs and XSDs to JSON Schema.