Dart apps function exclusively on a single thread by default. This technique frequently makes writing the code simpler and is quick enough to prevent poor app performance or stuttering animations. However, there are times when we might need to carry out an expensive calculation, such parsing a huge JSON document. The users will feel jank if this process takes more than 16 milliseconds.   We must run costly computations like this in the background to prevent this jank. This means scheduling work for a different thread on Android. We can employ a different Isolate in Flutter. The following are the procedures for parsing JSON in Flutter:   Step 1- Adding the http package.   Step 2- Using the http package to send a network request.   Step 3- Making the response into a gallery of images.   Step 4- Transferring this project to a different isolation.