User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:64.0) Gecko/20100101 Firefox/64.0 Steps to reproduce: (1) Opened dev tools. (2) Loaded a page which requests (ajax) for 1.62MB of application/json data. (3) Opened Network, click on the request to inspect it. (4) Clicked on the "Response" tab. Actual results: (i) Firefox displays a purple message claiming that the JSON is malformed (it absolutely isn't invalid, the app on the page parses that data with JSON.parse without any problem). It appears that FF dev tools is truncating the JSON string before parsing it. (ii) After about 3 seconds, I get a spinning beach ball, and FF freezes completely and must be exited by force quit. Expected results: (i) Dev tools should should indicate the large JSON response is valid. (ii) Dev tools should allow me to inspect the data without crashing the browser. No problem in Chrome, FWIW.