Simple and perfect, 5 *****

Everything works great. Just a few suggestions:

1. When a badly encoded file fails to load, it simply shows a blank window. Can you provide some error details to help out?

2. Can you add auto-cleanup function to to clean badly formatted JSON, atleast for some simpler errors?

3. [IMPORTANT] I am not sure if you heard of AVRO format. Its basically JSON on steriods. You should look to support that format and add it as an in-app-purchase feature.

vrkiran about Cocoa JSON Editor