How To Pretty Print Or Format JSON String In JavaScript

Unknown to many, JSON.stringify has 2 additional parameters that allow us to format a JSON string.

To start off, you will need to parse the string into a JavaScript object, then back into a JSON string.

const jsonString =
  '{"car":"Audi","pet":"Dog","location":{"city":"Vienna","country":"Austria"}}'
const parsedJsonString = JSON.parse(jsonString) // JavaScript object

const formattedJsonString = JSON.stringify(parsedJsonString, null, 2) 
console.log(formattedJsonString)
/**
  "{
    \"car\": \"Audi\",
    \"pet\": \"Dog\",
    \"location\": {
      \"city\": \"Vienna\",
      \"country\": \"Austria\"
    }
  }" 
*/

The 3^rd (i.e. space) parameter is of interest to us as it inserts whitespace into the output JSON string. It accepts a number (e.g. 2), which represents the amount of whitespace characters inserted at each line and indentation.