Sentinel: Your Web-Performance Watchman

Borders on responsive images

Written by on CSS Wizardry.

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  1. Demo

This is a quick-tip type post, nothing major but a simple and effective tip for getting responsive borders on responsive images in your responsive designs.

As we know all too well, we can’t specify borders as percentages. This is a major annoyance if you’re working (or attempting to work) large borders into a responsive design. It may not be all that difficult with images, it turns out.

Instead of applying something like this:

  border:5px solid red;

Simply use:

    padding:1%; /* A percentage that, when doubled and added to the above, makes 100%. */
    background:red; /* Color of the faux border. */


I made a jsFiddle and here is its output.

Now this does seem ridiculously obvious but a quick bit of Googling (other search engines are available) yielded nothing similar. Apologies is someone’s beaten me to this and I’m retreading old ground.

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Hi there, I’m Harry Roberts. I am an award-winning Consultant Web Performance Engineer, designer, developer, writer, and speaker from the UK. I write, Tweet, speak, and share code about measuring and improving site-speed. You should hire me.

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