How To Check If A File In Website Has Been Updated Or Not

Having the latest version of software is very important because it contains new features and bug fixes. I have a lot of portable tools such as AIMFix, HijackThis, RunScanner, RRT and etc in my USB flash drive and it can take up quite a lot of my time just to check if I have the latest version. Some files can easily be identified whether it has been updated or not because the website hosting the file displays very detailed version number and also date of last update. Even having those information, it is still very troublesome because I have to visit more than 20 sites just to check for software updates.

Here is how I easily check if a file or software hosted in website has been updated or not.

One of my favorite download manager FlashGet has a very useful built-in feature which can check if the downloaded file has been updated or not. If the downloaded file has been updated, it will automatically download the new file. For this to work, you MUST first download the file using FlashGet. Once downloaded, the file name will be moved to “Downloaded” category. When you want to check if the downloaded file has been updated or not, go to Downloaded category, you can either choose one or multiple files, and select “Check for update“.

If you’re wondering how FlashGet checks whether a file has been updated or not, it make use of “Last-Modified” information in HTTP header. Whenever you visit any HTTP URL using your web browser, there’s a HTTP request and response working in background which you don’t see at all. These headers include valuable information, such as identification of the remote server’s software, remote time and date, the MIME type and size of a file, and various other pieces of information.

I will show you 3 ways on how to get the last-modified information of a file. Let’s take the link of AIMFix (http://www.jayloden.com/AIMFix.exe) for an example.

1. ViewHEAD

- ViewHEAD is a free and portable tool that is able to show the hidden HTTP server response codes for a URL. As you can see from the image above, I entered the AIMFix download link and it displays the Last-Modified date Fri, 21 Mar 2008 13:57:30 GMT.
[ Download ViewHEAD ]

2. Web-sniffer

- Web-sniffer is a web based free service to view HTTP request and response header. If you don’t want to download ViewHEAD, you can use Web-sniffer.
[ Visit Web-sniffer ]

3. LiveHTTPHeaders for Firefox

- If you don’t like to view HTTP headers using a ViewHEAD or web-sniffer, you can view it directly from Firefox browser. After installing the LiveHTTPHeaders extension, go to Tools > Live HTTP headers. Make sure capture is checked and then visit the URL. It will capture and show you the HTTP Header.
[ Download LiveHTTPHeaders extension for Firefox ]

So what changes the “last-modified” information? Actually it is pretty simple. When you upload a new file overwriting the old one, the last-modified data will automatically be updated to the current date and time of the server. Using this method to check for file updates is not 100% accurate because if the website owner accidentally deleted the file and then reupload the same file, the last-modified time and date will be updated but it is in fact still the same file. I think FlashGet “check for update” feature will be better if it can check for file size differences together with last-modified information.