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T-Mobile UK (and possibly other areas where T-Mobile operate) have a system that automatically compresses images when using the internet on their network via a mobile broadband stick or via mobile phones. This is to save the amount of data transferred over their network as this is limited to 7.2mbps shared between all users connected to the cell you are using. Below is an example of a compressed and an uncompressed image.

Google Images Logo - Uncompressed
Google Images Logo - Uncompressed
Google Images Logo - Compressed
Google Images Logo - Compressed

Some of the mobile broadband software for the sticks allow you to manually adjust the level that images get compressed and even turn it off but a lot of the newer software versions on some mobile broadband sticks don't which can be annoying for people who don't want the compression. Good news, though! For Firefox users, I have found a solution that allows you to disable the compression regardless of what mobile broadband stick is used and on any operating system Firefox supports.

1. Click here to download the Modify Headers addon for Firefox.
2. Restart Firefox to complete the addon installation.
3. Go Tools -> Modify Headers.
4. In the top box, select Add on the drop down box, enter "pragma" in the first text box and "no-transform" in the second. After this, press Add.
5. Repeat step 4 and add another one but enter "Cache-Control" in the first text box and "no-cache" in the second. The Modify Headers screen should then look like the screenshot below.
Firefox Modify Headers Addon
Firefox Modify Headers Addon
6. Click Configuration and tick "Always On".
7. Restart Firefox.

Assuming you have done everything correctly, all images should now show in standard quality and not be compressed.

Please be aware that turning off compression can result in pages taking longer to load. It will not result in you reaching your Fair Usage Policy data limit faster, though, as T-Mobile count the uncompressed data transfer even when you are getting compressed images delivered to your computer.

As mentioned, this is only currently available for Firefox at the moment although I am looking into the possibility of releasing a simple application for Windows that will work with all browsers and allow you to adjust the compression level. As far as I can tell, compression is decided in each HTTP request sent so it should just be a case of intercepting HTTP requests, adding something onto them and then sending them to their original destination. I will then be looking into what can be done about compression on phone based internet.

I have been suggesting to T-Mobile for a while they should do one of two things to solve this issue. The first would be an easier option and would involve allowing us to login to My T-Mobile and setting compression on a per line basis from in there. The second option would take a little longer but would be well worth it. Currently, T-Mobile have different software each of the mobile broadband sticks they offer which I can only imagine must be a nightmare to offer technical support for. Vodafone UK have a nice piece of software that includes drivers for ALL mobile broadband sticks they offer and have previously offered. It has a single common interface and generally works better than the way T-Mobile do things.

I am a technology enthusiast living up in Carlisle, Cumbria in the UK and am the managing director of Its Elixir which sells Henna Hair Care Products and Ear Candles, Craig Brass Systems which creates and custom develops quality software and LonsdaleNET which delivers high speed wireless and fibre optic broadband in Cumbria.