Do text based browsers reduce network traffic?
Web server doesn't send "entire website", but documents that browsers request.
For example when you access https://www.google.com/ the browser queries server for the document https://www.google.com/. The server processess the request and sends back some HTML code.
Then the browser checks what the server has sent. In this case it's HTML webpage, so it parses the document and looks for referenced scripts, stylesheets, images, fonts etc.
At this stage the browser has finished downloading that document, but still doesn't have downloaded referenced documents. It can choose to do so or to skip them. Regular browsers will try to download all referenced documents for best viewing experience. If you have an ad blocker (like Adblock) or privacy plugin (Ghostery, NoScript), it may block some resources too.
Then the browser downloads referenced documents one by one, each time asking the server explicitly for a single resource. In our Google example the browser will find following references, just to name a few of them:
- https://www.google.com/images/srpr/logo11w.png (Google logo)
- https://www.google.com/textinputassistant/tia.png (keyboard icon)
- https://ssl.gstatic.com/gb/images/i1_3d265689.png (some combined images, trick used to reduce number of browser requests)
(actual files may be different for different users, browsers and sessions and may change over time)
Text-based browsers don't download images, Flash files, HTML5 video etc. so they download less data.
@NathanOsman makes a good point in comments: Sometimes small images are embedded directly in HTML documents and in those cases downloading them cannot be avoided. This is another trick used to reduce number of requests. They are very small, though, otherwise the overhead of encoding binary file in base64 is too big. There are few such images on Google.com: (base64 encoded size / decoded size)
- 19×11 keyboard icon (106 B / 76 B)
- 28×38 microphone icon (334 B / 248 B)
- 1×1 px transparent GIF (62 B / 43 B) which shows up in Chrome Dev Tools Resources tab, but I couldn't find it in the source - probably added later with JavaScript
- 1×1 px corrupted GIF file that appears twice (34 B / 23 B). Its purpose is a mystery to me.
I would suspect that they do. I don't believe that text-based browsers will (by default) even download resources such as images or external entities, such as fonts (if needed), scripts, etc.
I did some basic testing with tcpdump trying to get this IANA page (http://www.iana.org/domains/reserved) with both lynx and then wget, and here were my results (HTTP commands only, I can provide the rest if needed).
lynx http://www.iana.org/domains/reserved
4 0.072774 xx.xx.xx.xx -> 192.0.32.8 HTTP GET /domains/reserved HTTP/1.0
10 0.146971 192.0.32.8 -> xx.xx.xx.xx HTTP HTTP/1.1 200 OK (text/html)
wget -p http://www.iana.org/domains/reserved
4 0.072139 xx.xx.xx.xx -> 192.0.32.8 HTTP GET /domains/reserved HTTP/1.0
22 0.145905 192.0.32.8 -> xx.xx.xx.xx HTTP HTTP/1.1 200 OK (text/html)
28 0.219381 xx.xx.xx.xx -> 192.0.32.8 HTTP GET /robots.txt HTTP/1.0
30 0.291877 192.0.32.8 -> xx.xx.xx.xx HTTP HTTP/1.1 200 OK (text/plain)
32 0.292550 xx.xx.xx.xx -> 192.0.32.8 HTTP GET /_css/2013.1/screen.css HTTP/1.0
94 0.440388 192.0.32.8 -> xx.xx.xx.xx HTTP HTTP/1.1 200 OK (text/css)
100 0.514652 xx.xx.xx.xx -> 192.0.32.8 HTTP GET /_css/2013.1/print.css HTTP/1.0
132 0.660071 192.0.32.8 -> xx.xx.xx.xx HTTP HTTP/1.1 200 OK (text/css)
138 0.733546 xx.xx.xx.xx -> 192.0.32.8 HTTP GET /_img/bookmark_icon.ico HTTP/1.0
154 0.878227 192.0.32.8 -> xx.xx.xx.xx HTTP HTTP/1.1 200 OK (application/octet-stream)
160 0.950713 xx.xx.xx.xx -> 192.0.32.8 HTTP GET /_js/2013.1/jquery.js HTTP/1.0
277 1.172095 192.0.32.8 -> xx.xx.xx.xx HTTP HTTP/1.1 200 OK (application/x-javascript)
283 1.244571 xx.xx.xx.xx -> 192.0.32.8 HTTP GET /_js/2013.1/iana.js HTTP/1.0
285 1.317059 192.0.32.8 -> xx.xx.xx.xx HTTP HTTP/1.1 200 OK
287 1.317609 xx.xx.xx.xx -> 192.0.32.8 HTTP GET /_img/2013.1/iana-logo-header.svg HTTP/1.0
332 1.464356 192.0.32.8 -> xx.xx.xx.xx HTTP/XML HTTP/1.1 200 OK
337 1.536749 xx.xx.xx.xx -> 192.0.32.8 HTTP GET /_img/2013.1/icann-logo.svg HTTP/1.0
348 1.610449 192.0.32.8 -> xx.xx.xx.xx HTTP/XML HTTP/1.1 200 OK
353 1.682727 xx.xx.xx.xx -> 192.0.32.8 HTTP GET /_css/2013.1/fonts/OpenSans-Light.ttf HTTP/1.0
658 2.552776 192.0.32.8 -> xx.xx.xx.xx HTTP HTTP/1.1 200 OK (application/octet-stream)
663 2.625015 xx.xx.xx.xx -> 192.0.32.8 HTTP GET /_css/2013.1/fonts/OpenSans-Regular.ttf HTTP/1.0
926 3.063537 192.0.32.8 -> xx.xx.xx.xx HTTP HTTP/1.1 200 OK (application/octet-stream)
932 3.135931 xx.xx.xx.xx -> 192.0.32.8 HTTP GET /_css/2013.1/fonts/OpenSans-Semibold.ttf HTTP/1.0
1216 3.573481 192.0.32.8 -> xx.xx.xx.xx HTTP HTTP/1.1 200 OK (application/octet-stream)
1222 3.645984 xx.xx.xx.xx -> 192.0.32.8 HTTP GET /_css/2013.1/fonts/OpenSans-Bold.ttf HTTP/1.0
1500 4.012966 192.0.32.8 -> xx.xx.xx.xx HTTP HTTP/1.1 200 OK (application/octet-stream)
1506 4.085693 xx.xx.xx.xx -> 192.0.32.8 HTTP GET /_css/2013.1/fonts/Inconsolata.otf HTTP/1.0
1584 4.304016 192.0.32.8 -> xx.xx.xx.xx HTTP HTTP/1.1 200 OK (application/octet-stream)
1589 4.376612 xx.xx.xx.xx -> 192.0.32.8 HTTP GET /_img/2011.1/icons/icon_alert.png HTTP/1.0
1592 4.449311 192.0.32.8 -> xx.xx.xx.xx HTTP HTTP/1.1 200 OK (PNG)
1594 4.449930 xx.xx.xx.xx -> 192.0.32.8 HTTP GET /_img/2013.1/iana-logo-homepage.png HTTP/1.0
1627 4.596125 192.0.32.8 -> xx.xx.xx.xx HTTP HTTP/1.1 200 OK (PNG)
1633 4.668596 xx.xx.xx.xx -> 192.0.32.8 HTTP GET /_img/2013.1/[email protected] HTTP/1.0
1704 4.895581 192.0.32.8 -> xx.xx.xx.xx HTTP HTTP/1.1 200 OK (PNG)
1710 4.968097 xx.xx.xx.xx -> 192.0.32.8 HTTP GET /_css/2011.1/fonts/OpenSans-Light.ttf HTTP/1.0
1982 5.364584 192.0.32.8 -> xx.xx.xx.xx HTTP HTTP/1.1 200 OK (application/octet-stream)
1988 5.438091 xx.xx.xx.xx -> 192.0.32.8 HTTP GET /_css/2011.1/fonts/OpenSans-Regular.ttf HTTP/1.0
2243 5.830353 192.0.32.8 -> xx.xx.xx.xx HTTP HTTP/1.1 200 OK (application/octet-stream)
2249 5.902861 xx.xx.xx.xx -> 192.0.32.8 HTTP GET /_css/2011.1/fonts/OpenSans-SemiBold.ttf HTTP/1.0
2259 5.976674 192.0.32.8 -> xx.xx.xx.xx HTTP HTTP/1.1 404 NOT FOUND (text/html)
2263 6.047876 xx.xx.xx.xx -> 192.0.32.8 HTTP GET /_css/2011.1/fonts/OpenSans-Bold.ttf HTTP/1.0
2533 6.415590 192.0.32.8 -> xx.xx.xx.xx HTTP HTTP/1.1 200 OK (application/octet-stream)
2539 6.487909 xx.xx.xx.xx -> 192.0.32.8 HTTP GET /_css/2011.1/fonts/Inconsolata.otf HTTP/1.0
2616 6.720477 192.0.32.8 -> xx.xx.xx.xx HTTP HTTP/1.1 200 OK (application/octet-stream)
So I realize this is not a great test as wget may download resources that a browser might not download, but the example I think holds - there are many more requests required to render content on a GUI browser. As such, it GUI browsers will generally cause more network traffic than text based browsers.