Enter a URL, secure or not, into the HTTP header lookup form and analyze the output and raw HTML for the given URL using a freely available online script provided by the team at Webmaster.net.

HTTP Header Check Tool

Essentially what the tool does is fetches the headers of a site, and the source, so that you can analyze the status code and check what information the server sends, including cookies, server caches, etc.

What Exactly Are HTTP Headers?

HTTP is an acronym which stands for “HyperText Transfer Protocol.” While FTP (File Transfer Protocol) can be used in a web browser, just about everything that is sent to your computer through the browser is sent over HTTP. For example, upon visiting this article your browser (Chrome, IE, FireFox, Safari, Opera, etc.) sent several HTTP requests and received an HTTP Response for each one.

The core part of the communication for this protocol are the HTTP Headers. They carry information that has to do with the web browser being used, the actual web page being fetched, and so on.

Even though they are transmitted together, you will only see the HTML output for a given web page when “viewing the source,” and not the actual HTTP Headers. The Headers though can help a webmaster with troubleshooting a web page or site, hence the use of a header check tool.

Common Request Types

Three commonly used “request types” include GET, POST, and HEAD. GET and POST are even more common and used when coding HTML forms.

A GET request is a simple way to retrieve a document from the server, and is the primary method for retrieving JavaScript, HTML, CSS, images and so on. Simple forms will use GET requests as well. More complicated forms that contain more data, and file upload forms will use the POST request method.

HEAD is similar to GET but the only thing returned is the response code and the HTTP headers, not the content. This provides the browser methods to check for new versions of cached documents and also a way to see if the document even exists.

After HTTP requests are sent by the browser to the server, the response will include the protocol (and version), the status, the HTTP headers which are colon-separated name-value pairs in clear-text string format, and in some cases the content as well.

HTTP Status Codes

Just after the numerical portion of the status code is a short message. The status code response of 200 means that the request was sucessful and after the headers, the content will be output to the browser. 404, as you probably are aware, means the page was not found.

>> 200’s are used for “success” requests
>> 300’s for redirects
>> 400’s are “request” problem statuses
>> 500’s are “server” problem statuses

What’s The Use Of An HTTP Header Check Tool?

The Headers returned by the web browser can help a webmaster get closer into figuring out what the problem is with a given web page, if any at all. It can also indicate which cookies are being created by a page, which can help with troubleshooting. Or it can help you figure out why you can only look at three profiles on the Plenty of Fish dating site when not logged in (sorry Markus).

Another great use is if you are redirecting a URL. Using the correct type is a very important factor for Search Engine Optimization (SEO) purposes, so knowing the type (301 Moved Permanently; 302 Moved Temporarily) that is returned, can assist in knowing whether to change it or not (hint: use 301).

Video: Demonstration Of Its Use

Below is a video for using the HTTP Header Check Tool. By the time that you read this, the tool may have been upgraded or improved upon in some way, but the demo should still suffice as an overview of how it is used.