единственное расширение, которое на header text/html преобразует в красивый json

At last a convenient way to see JSON files without opening the developer tools.

The tools I found that can really be used on Firefox are great! jsonview doesn't work properly on Firefox. I have been distressed for a long time, thank you very much.

The only one I found, that worked on Firefox Quantum 65.0.1 (64-bit).
Plus, it has good custom visual options. Great add-on!
Thank you, Mr. Lauri Rooden.

Very Good

Very NICE tool for developers. The only bad thing is that this addon breaks down the XML view when you open an XML document in firefox. If this is fixed, i will change my rating to 5 stars!

Great as what I expected, especially custom theme adds up the score a lot!

Nice representation and easy keyboard navigation through the JSON document. Just all I need. Thanks!