By default, the response of all the requests is not formatted. It returns an unformatted JSON string in a single line:

curl -XGET http://localhost:9200/catalog/_doc/1

The following response is not formatted:

{"_index":"catalog","_type":"product","_id":"1","_version":3,"found":true,"_source":{
 "sku": "SP000001",
 "title": "Elasticsearch for Hadoop",
 "description": "Elasticsearch for Hadoop",
 "author": "Vishal Shukla",
 "ISBN": "1785288997",
 "price": 26.99
}}

Passing pretty=true formats the response:

curl -XGET http://localhost:9200/catalog/_doc/1?pretty=true
{
 "_index" : "catalog",
 "_type" : "product",
 "_id" : "1",
 "_version" : 3,
 "found" : true,
 "_source" : {
 "sku" : "SP000001",
 "title" : "Elasticsearch for Hadoop",
 "description" : "Elasticsearch for Hadoop",
 "author" : "Vishal Shukla",
 "ISBN" : "1785288997",
 "price" : 26.99
 }
}

When you are using the Kibana Console UI, all responses are formatted by default.