Within 3 seconds a website needs to tell visitors what the business has to offer. That's where your headline comes in. It may only be a few words, but it's one of the most important piece of copy on your website. Keep the headline itself clear and simple. No more than 7 words!
Your sub-headline should supplement the headline by offering a brief description of what you do or what you offer. This can be done effectively by zeroing in on a common pain point that your product or service solves. Avoid jargon. No more than 14 words!