Web servers provide information about the response body in the response header.
To see only the header, we can run:
$ wget --spider --server-response https://www.gutenberg.org/cache/epub/100/pg100.txt
Spider mode enabled. Check if remote file exists.
--2019-10-14 09:13:55-- https://www.gutenberg.org/cache/epub/100/pg100.txt
Resolving www.gutenberg.org (www.gutenberg.org)... 152.19.134.47
Connecting to www.gutenberg.org (www.gutenberg.org)|152.19.134.47|:443... connected.
HTTP request sent, awaiting response...
HTTP/1.1 200 OK
Server: Apache
Content-Location: pg100.txt.utf8.gzip
Vary: negotiate
TCN: choice
Last-Modified: Sun, 01 Oct 2017 05:16:47 GMT
X-Frame-Options: sameorigin
X-Connection: Close
Content-Type: text/plain; charset=utf-8
Content-Encoding: gzip
X-Powered-By: 1
Content-Length: 2023394
Date: Mon, 14 Oct 2019 13:13:55 GMT
X-Varnish: 1859043781 1856607983
Age: 104391
Via: 1.1 varnish
Length: 2023394 (1.9M) [text/plain]
Remote file exists.
Once we see that the content is actually compressed with gzip, we can use gunzip to decompress it:
$ wget -O - https://www.gutenberg.org/cache/epub/100/pg100.txt | gunzip -c > pg100.txt
When the page is displayed in a modern browser, you will find that the browser has done this work for us.