How to use the JSON Blueprint Utilities Plugin in Unreal Engine 5

This experimental plugin lets you work with json strings or files -- allowing you to pull data from external files into your project using only blueprint. 

Enable the Plugin

Go to the Edit menu and find Plugins at the bottom of the drop down.
In the Plugins window search for 'json'
Click the check box next to the Json Blueprint Utilities

This plugin is in 'BETA' still (as of July 2023 publishing) so it's not recommend for production releases so it's use at your own risk. :) It's pretty cool tho! 

Creating a simple BP that uses the JSON utils


Make a json file

  1. Outside of Unreal  - open a text editor like VS Code or Notepad.
  2. Copy and past this json code into a new text file:

    { "name": "Sting", "damageDiceAmount": 1, "damageDie": 8, "type": "sword", "description": "Elven forged sword that glows when enemies are nearby." }

  3. Save as sting.json to your desktop or some easy to find spot.


Create a simple actor blueprint. 

  1. Inside the Event graph pull off Begin Play Node and search for json in the pop up. 
  2. Find the Load Json from File node and add it to the event graph
  3. Right click on the File input on the Load Json from File node and make a new variable.
  4. Compile and then click the ... on the File variable - find the json file you created in the finder.
  5. Now drag off the Json Object ouput on the load file node and search for Get Field
  6. in the Field name of the new node - type: name
  7. Now drag off the value output of Get Field and add a Print String
  8. Compile and save!
  9. Add this new bp actor to your scene and run it.
  10. When you run your game now a debug message in the top left should print 'Sting' by loading the json and finding the value. 

Working with Json Arrays

One issue I had with this utility was figuring out how to get arrays to work.

If you drag of the json object in the wrong direction it defaults to wild card vars that don't seem to work.

Luckily there was a post on the Unreal Forums asking about json arrays and user / marketplace creator Sumpremitive gave a great answer.

Find Unreal Forum post here:
https://forums.unrealengine.com/t/how-do-i-loop-through-json-array/654870/7

To get the arrays to work you need to wire everything backwords order so that the variables all get set to expected types.

See the gif below:

Setting up a data directory for your project

You want a directory that remains consistent for when you ship your game.

Here is a way I did it. 

In the Windows File Explorer - navigate to your project folder.
Open the main folder and find the Content folder.
Inside the content folder add a new folder called Data. 
Add you json files to this new folder. 

I think to build with this data directory you need to add it to the Project Packaging so it becomes part of the build but remains a visible folder -for modding!

Go to Project Settings -> Project Packaging. 

Find the Additional Non-Asset Directories to Copy section. Add your new Data folder. 

Now when you build this folder will go with the project.