Avoid blinking if possible - it annoys people.
But you can do it with JS / jQuery as follows:
setInterval(jQuery('.blinking').toggle, 1500 );
This will show / hide something with a blinking class every 1.5 seconds.
So, in HTML you would do:
<span class="blinking">hello!</span>
But again, think very carefully if it should blink!
If you need something specific to get the user's attention (and for some reason, regular accent / highlighting / etc is not good enough), then instead of turning on blinking (where the text disappears for half the time), consider changing color or blinking underline / border or the like.
Most importantly, if something is important enough to visually annoy the user, then it should remain readable.
Peter Boughton
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