Working with large JSON output can be a pill, especially when the server strips white-space or makes no effort at formatting the response for human-readability.

Having previously looked for a solution to make this easy, and not finding the right Google-majik to find it, I came across this article that talks about BBEdit’s Unix filtering abilities: BBEdit: Its Unix Support Doesn’t Suck Either, Part 2

I created this Python script that applies JSON pretty-print to text selected in the editor window:

#!/usr/local/bin/python
import fileinput
import json
if __name__ == "__main__":
  jsonStr = ''
  for a_line in fileinput.input():
    jsonStr = jsonStr + ' ' + a_line.strip()    
  jsonObj = json.loads(jsonStr)  
  print json.dumps(jsonObj, sort_keys=True, indent=2) 

1. Create the script (name it what you will, I named mine “PrettyJSON.py”), and save it in the “Unix Filters” folder for BBEdit (as described in the above article.
2. Copy some JSON into BBEdit, select it, and apply the filter.

Voila! Human-readable JSON.

UPDATE: If you are using BBEdit 10…

• The ”PrettyJSON.py” script should be placed here: “~/Library/Application Support/BBEdit/Text Filters”
• Run the filter using the menu sequence: Text->Apply Text Filter->PrettyJSON

[NOTE: Also works on TextWrangler, the free, light version of BBEdit.]

See also:

BBEdit

TextWrangler