Welcome to WebmasterWorld Guest from

Forum Moderators: bakedjake

Message Too Old, No Replies

Mobile Broadband - ISP script injection can and does break JS/CSS

USed to compress images, this script can destroy a site's functionality.



9:26 am on Dec 15, 2012 (gmt 0)

WebmasterWorld Senior Member 10+ Year Member

I've been without a proper broadband line for a few weeks, due to a wait with ISP for a connection at my new office.

I've been reluctantly using Mobile Broadband for this period and have noticed a worrying trend - sites of all shapes and sizes are breaking due a script my ISP has implemented to compress all js/css/html and render images at about 90% compression.

I'd hoped the script was located on the dongle itself, so disabled the software and connected through prefs, no luck. The script is served by the ISP directly.

Site's that I've noticed problems include some of the largest social media, shopping and bookmarking services, amongst others. So would indicate it's not just affecting jQuery (as I first thought) but also Bootstrap and custom js.

Anyone else notice this? Could be a minefield if a client is using Mobile BB - not to mention their customers... useful to know, but #*$! hell, why should we have to accommodate this sloppy code with no option to disable or bypass?

(note mobile browsing natively, using HTTPS or via mobile tethering doesn't seem to use the same archaic methods).


11:45 am on Dec 15, 2012 (gmt 0)

WebmasterWorld Senior Member 10+ Year Member

Any idea, or are you able to set-up a test to see if the same inline processing takes place if all text/* content is served gzipped?

That's not to say that the same proxy isn't manipulating the Accept-Encoding header on outbound requests of course...


12:28 pm on Dec 15, 2012 (gmt 0)

WebmasterWorld Senior Member 10+ Year Member

On further investigation it looks like you can ask the server to bypass the compression scripts using HTTP header: Cache-Control: no-transform.

More: [stuartroebuck.blogspot.co.uk...] and [stuartroebuck.blogspot.co.uk...]

Not tried it yet - will test later.

Featured Threads

Hot Threads This Week

Hot Threads This Month