Friction is any obstacle between a visitor's intent and your conversion goal. Some friction is obvious: a 15-field form, a page that takes 8 seconds to load, a popup blocking the CTA. Most friction is subtle: unclear pricing, ambiguous button copy, a form that asks for a phone number when you only need an email.
The insidious thing about friction is that visitors don't complain about it. They don't send you feedback saying "Your form was too long, so I left." They just leave. You never see the conversion that didn't happen because of the extra form field, the missing trust badge, or the confusing pricing table.
The three types of friction
Cognitive friction: The visitor has to think too hard. Confusing navigation, unclear value proposition, too many choices, jargon-filled copy. Fix: simplify everything.
Emotional friction: The visitor doesn't trust you. No social proof, no security badges, no refund policy, no clear contact information. Fix: add trust signals proportional to what you're asking for.
Mechanical friction: The action itself is too hard. Long forms, account creation required, slow page loads, broken mobile experience. Fix: reduce steps to the absolute minimum.