In our Integration projects, especially nowadays on Azure Integration Services, we often work with JSON messages. And despite Logic App Designer allowing us to generate a JSON schema based on a JSON payload (or JSON message), there are many situations where we need the opposite! We want to generate a dummy message from the JSON Schema to test our Logic Apps solutions, or, now, our Data Mapper maps.
Unfortunately, there aren’t any out-of-the-box capabilities inside Logic Apps or the new Data Mapper to generate a dummy message.
I’m doing a lot of demos and sessions on the new Data Mapper, and you cannot imagine the times I forget the input message for each specific map, and I find myself constantly looking for that information.
In order to accomplish that, we usually use free online tools like this one: https://www.liquid-technologies.com/online-schema-to-json-converter, but what annoys me about these online tools is that all data is stored in their log files, and sometimes, for privacy/security concerns, that can be a problem. For this reason, I decided, along with my team, to start creating these free tools with source code available on GitHub to avoid raising the same suspicions.
📝 One-Minute Brief
Generate sample JSON documents from JSON Schemas using this open‑source desktop tool. Version 2.0 adds the ability to load local JSON files, helping you test Logic Apps and Data Mapper scenarios without sharing sensitive data online.
Create a sample JSON document from a JSON Schema Tool
Create a sample JSON document from a JSON Schema Tool is a straightforward Windows tool that allows you to create a JSON Document based on the JSON Schema we provide. No data is stored in log files.

In this new version, we will be able to load a JSON message from our local hard drive.
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Credits
- Luis Rigueira | Member of my team and one of the people responsible for developing this tool.