Chunked transfer encoding is an HTTP/1.1 feature that enables keep-alive requests.
If you want to avoid chunked encoding send requsets to the server using HTTP/1.0. A request with HTTP/1.0 would look like this
GET /index.html HTTP/1.0
The problem with HTTP/1.0 is that it required a new connection for each resource downloaded. Since each html document contains many images, css, and js files, you might need tens of connection to download an entire page using HTTP/1.0. Establishing each connection is slow. When HTTP/1.1 was invented, a design goal was to allow pipelining and re-use of connections. Now browsers can download the page and all of its images in a single connection. The webserver responds in "chunks". Each chunk starts with the size of the chunk. Once that size has been downloaded, the browser can make another request on the same connection and receive more chunked data without starting up a new connection.