Please Whitelist This Site?

I know everyone hates ads. But please understand that I am providing premium content for free that takes hundreds of hours of time to research and write. I don't want to go to a pay-only model like some sites, but when more and more people block ads, I end up working for free. And I have a family to support, just like you. :)

If you like The TCP/IP Guide, please consider the download version. It's priced very economically and you can read all of it in a convenient format without ads.

If you want to use this site for free, I'd be grateful if you could add the site to the whitelist for Adblock. To do so, just open the Adblock menu and select "Disable on". Or go to the Tools menu and select "Adblock Plus Preferences...". Then click "Add Filter..." at the bottom, and add this string: "@@||^$document". Then just click OK.

Thanks for your understanding!

Sincerely, Charles Kozierok
Author and Publisher, The TCP/IP Guide

NOTE: Using software to mass-download the site degrades the server and is prohibited.
If you want to read The TCP/IP Guide offline, please consider licensing it. Thank you.

The Book is Here... and Now On Sale!

The whole site in one document for easy reference!
The TCP/IP Guide

Custom Search

Table Of Contents  The TCP/IP Guide
 9  TCP/IP Application Layer Protocols, Services and Applications (OSI Layers 5, 6 and 7)
      9  TCP/IP Key Applications and Application Protocols
           9  TCP/IP Application Layer Addressing: Uniform Resource Identifiers, Locators and Names (URIs, URLs and URNs)
                9  Uniform Resource Locators (URLs)

Previous Topic/Section
URL Relative Syntax and Base URLs
Previous Page
Pages in Current Topic/Section
Next Page
URL Obscuration, Obfuscation and General Trickery
Next Topic/Section

URL Length and Complexity Issues
(Page 2 of 4)

Reasons Why Long URLs are Common

The point that many elements in URL syntax are optional is important. The majority of the time, most of these optional parts are omitted, which makes URLs much simpler in practical use than they are “on paper”. For example, even though an HTTP URL theoretically contains a user name, password, host, port, path, query and bookmark, most URLs use only a host name and a path. This is what helps keep URLs short and easy to use.

Despite this, you will still find some rather long URLs used on the Internet. Here are some of the most common reasons why.

Long DNS Domain and Host Names

Some people don't realize that long host names are hard to remember. If you run the “Super Auto Body Shop & Pizza Parlor”, having a Web site called “” will make it easier for your customers to find you than trying to register “”. Yet DNS names of 15, 20 or even more characters are surprisingly common.

Long Document or Directory Names

Similarly, short file names are better than long ones, and again, many people don't think about this before putting files on the Internet, which makes things more difficult for those who must access them.

Use of “Unsafe” Characters

URLs have a mechanism for dealing with “unsafe” characters, but it makes them longer and harder to decipher. Suppose you have a file named:

“{ABC Corp} budget; draft #3; third quarter 2004.htm”

The URL for this will have to be:


The original long file name was readable, but the URL is a mess because of the special character encodings.

Naming the file “ABC budget draft 3, 3Q2004.htm” would be a better choice, and still includes enough information to be understandable. Even better, you could replace the spaces with underscores, to avoid the need for “%20”s entirely: “ABC_budget_draft 3,_3Q2004.htm”.

Parameter Strings

In HTTP URLs, the syntax for specifying a query (following a question mark character) is often used to allow a Web browser to send various types of information to a Web server, especially parameters for interactive queries. These parameter strings can get quite lengthy. For example, I typed in a query to the great Web search engine Google to find recipes for potato salad. This is what the URL for one of the recipe files looks like:


Almost all of that consists of parameters that tell the Google server exactly what document I want based on my query. It is necessary, but still cumbersome.

Previous Topic/Section
URL Relative Syntax and Base URLs
Previous Page
Pages in Current Topic/Section
Next Page
URL Obscuration, Obfuscation and General Trickery
Next Topic/Section

If you find The TCP/IP Guide useful, please consider making a small Paypal donation to help the site, using one of the buttons below. You can also donate a custom amount using the far right button (not less than $1 please, or PayPal gets most/all of your money!) In lieu of a larger donation, you may wish to consider purchasing a download license of The TCP/IP Guide. Thanks for your support!
Donate $2
Donate $5
Donate $10
Donate $20
Donate $30
Donate: $

Home - Table Of Contents - Contact Us

The TCP/IP Guide (
Version 3.0 - Version Date: September 20, 2005

Copyright 2001-2005 Charles M. Kozierok. All Rights Reserved.
Not responsible for any loss resulting from the use of this site.