What is CGI-Bin and What Does it Do?

Posted on by Ronald Caldwell
Reading Time: 5 minutes

The World Wide Web has been a staple of scientific information-sharing, communication, entertainment, and eCommerce since its inception in 1989 by a British scientist, Tim Berners-Lee. In 1989, scientists at CERN (European Council for Nuclear Research) needed a way to share information with other institutions regarding the evolving information associated with their fields.

By 1994, the technology had gone global; nearly 10,000 servers were already online, and 10 million users had access to the web. Over time, new technologies replaced the old framework until it became the internet we know today. The coding system also transformed, requiring server communications with external databases and information sources.

For communication between the program and server or application, there needed to be a middle ground or a proxy to pass along the request from the web server to the database. CGI was created out of this need and is a standard interface in web applications. 

What is CGI-Bin?

CGI stands for Common Gateway Interface and is the pathway that your requests, scripts in this case, communicate with your hosting server. CGI programs interact with the Hypertext Transfer Protocol (HTTP) and with Hypertext Markup Language (HTML) in general. CGI acts as a pathway for information sharing between the server and the application. When you think about how the internet came to be, it’s fitting that the process should mirror the scientist’s desire to share information more conveniently.

CGI is an industry standard because it can be written in any language if it is in compliance with environmental restrictions, or the constraints and limitations imposed by the server environment in which the CGI script is executed. The "Bin" acts as it does in the physical world. Bins are used for storage and organization, so the CGI-Bin is a storage location on your server where executable programs are housed until needed. The programs in the CGI-Bin directory are called CGI scripts; these scripts generate dynamic webpages and provide added function and purpose to your webpages.

Using these scripts, you can process requests from visitors to your website, send data, manipulate images, generate forms, and more.

What Does CGI-Bin Do, and Why Does it Matter?

When a visitor requests a page from your server, the web server looks in the CGI-Bin directory for the file. If a matching CGI script is identified, it runs, and its output is integrated into the webpage shown in the browser. This allows website administrators to deliver dynamic content and interactive elements on their websites.

Much like bins help keep items tidy, and in one place, a similar idea applies to the programs used in web server communications. The CGI-Bin stores CGI scripts for future use, and when the server requests a corresponding file from the CGI-Bin, it gets activated, and the output is relayed to the user's browser. A typical example of CGI-Bin utilization is the processing and storage of data from website visitors, such as search results or registration forms.

In addition to its primary role, a CGI-Bin allows users to modify images on-the-fly using scripting languages, such as PHP or Perl. CGI scripts enable developers to produce interactive content for web applications, and these scripts are stored in a safe and easily accessible location until the server requires them. Without a CGI-Bin, there would be no place for the scripts and no way to access the information that isn't directly readable by the client.

What is CGI-Bin Used For?

As scripts are sent to the web browser from the server, the CGI-Bin is usually referenced in the website’s URL address. As mentioned earlier, CGI-Bin is a storage location that interacts with your browser. These scripts provide the interactive functionality of your webpages. CGI-Bin acts as a folder for anyone who wants to run CGI scripts.

How Do You Run Your CGI-Bin Scripts?

We've established that a CGI program acts as a pathway for server requests, but they need permission for these scripts to run. We hinted at this process in the previous section, but to gain permission to run these scripts, they are accessed through the browser and, by necessity, through their URL address. The scripts need interpreters, usually written in programming languages like Perl, Python, and Ruby. Perl is likely the most common language used due to its powerful features. Plus, it's easy for novice programmers to learn.

Once you call the scripts using the necessary file extensions, you can execute the activity from your server in the specific areas you want and send the response to your browser application. But what if you encounter an issue and the script isn't executing or producing the result you expected? If so, you may need to troubleshoot the problem by accessing the CGI-Bin directory.

CGI programs are usually located in directories but can also run outside the directories based on the file extensions used. Although, this could be a potential security concern, which is why CGI programs are placed in specific directories.

What is the CGI-Bin Directory?

It's common for web servers to have a CGI-Bin directory. A directory is another virtual container that organizes files and comes in different forms; a tree-structured directory is the most common. The directories organize folders and provide a unique path under the parent directory, which is then governed by the root directory.

By this logic, the CGI-Bin directory is placed in a specific structure where the folder stores your Perl or Python scripts so they remain accessible by the server. Users with a web server can find the CGI-Bin directory in the configuration files.

Where Do You Find the CGI-Bin Directory?

Let's say you have a website that uses cPanel. In cPanel and other server file managers, you can find the CGI-Bin directory in the root directory panel, which is usually in the public or HTML folder. Here, administrators can monitor and configure all the programs running on the system.

What Happens if I Delete the CGI-Bin Folder?

The CGI-Bin is a default folder that is created on all new accounts and will make it so that your website is compatible with older scripts. Since it's possible to run CGI scripts outside the CGI-Bin, it isn’t necessarily bad if something happens to the CGI-Bin folder. You can delete the folder if you aren't using the CGI-Bin folder to store your scripts. Although, they don't use a lot of storage space on your server, so it's fine to leave them there.

If you delete the folder and find out later that your website needs the scripts, it’s easy to recreate and store them. A good indication of the necessity of the CGI-Bin folder is that once you delete it, you may notice that your website doesn't function correctly. If you're using scripts, it's safe to say that your site functionality may be affected. It’s not catastrophic, and it’s an easy fix.

Some experts consider CGI obsolete because its functions are represented in newer JavaScript and other web tools like PHP. In some ways, web development is moving away from CGI-Bin, but the technology helps add dynamic elements to your webpages. Also, broad compatibility further supports the continued use of the technology in development.


CGI is a continuing standard in web applications because it's a browser-compatible technology. If you have a paid web-hosting subscription, your site is likely using CGI scripting. If you know programming languages like C or Perl, you can experiment with your web server and explore CGI's various use cases.

Still, in its basic form, CGI serves as a pathway to execute web server requests to your browser application. Users can create stable and interactive experiences for their site visitors through this simple interaction. At Liquid Web, we understand that some projects are different and may call for flexible solutions.

Like CGI technology, Liquid Web’s hosting solutions are engineered to help you reach your goals faster. With the flexibility of a custom, multi-server platform, our expert team is dedicated to helping your business realize its true potential. Contact us for information or to get your services started.

Avatar for Ronald Caldwell

About the Author: Ronald Caldwell

Ron is a Technical Writer at Liquid Web working with the Marketing team. He has 9+ years of experience in Technology. He obtained an Associate of Science in Computer Science from Prairie State College in 2015. He is happily married to his high school sweetheart and lives in Michigan with her and their children.

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