Short answer: Once it's disconnected from the opener, a garage door should lift by hand with steady, moderate effort. If it feels very heavy, check that the release is fully disengaged and the slide lock is open. If it's still heavy, the springs are likely worn or broken. Stop lifting and call a professional. Only pull the release when the door is fully closed.

Most of the time you never lift your garage door. The opener does it. Then the power goes out, or the opener quits, and you find out the door is much harder to lift than you expected. Sometimes that's a simple setting. Sometimes it's the door telling you the springs are worn out.
The springs, not your arms, are supposed to carry the weight of the door. When they're working right, a disconnected door lifts with steady, moderate effort, moves smoothly, and stays put at about waist height when you let go. You should never have to strain, jerk it or lift with your legs like you're moving furniture.
Our guide on how to open a garage door in a power outage walks through the release step by step.
If the door is disconnected, unlocked and nothing is in the way, but it still feels very heavy, the springs are the likely cause.
Stop lifting. Lower the door gently if you can do it safely, keep clear and call a professional. Don't try to adjust or replace springs yourself. Our guide to a door that's out of balance covers the signs and the balance test, and our spring warning signs show what a broken spring looks like.
Not sure how your door is doing? Answer 7 quick questions and get a 0 to 100 score with an A to F grade in about 60 seconds. No email needed. Take the free checkup.
Sometimes the door isn't heavy so much as stiff. It moves in jerks, scrapes or sticks at one spot. That usually points to dry or worn rollers, dry hinges, a bent track, or seals rubbing too hard.
Here's a simple way to tell the two apart. With the door fully closed and released, lift it a foot or two and lower it gently. Skip this if you see a gap in a spring, a loose cable or a crooked door. A heavy door resists the whole way. A stiff door moves in fits and starts, or catches at the same spot, then moves more easily past it.
If lubricating and checking the seals doesn't help, or a roller looks cracked or wobbles, have a professional look at the rollers and track.
A door that's hard to lift by hand is just as hard on the opener. The opener is built to guide a balanced door, not to do the springs' job. A heavy door wears the opener out faster and makes a breakdown more likely. It also matters most on the day you need it, like during a storm or an outage. A yearly tune-up includes a balance test, which catches weak springs before you find out the hard way.
DoorGuard memberships start at $19 a month. It includes a yearly tune-up and safety inspection, priority scheduling if something goes wrong, and member savings on repair labor, with the price shown before any work begins. No contract, cancel anytime. See membership plans.
Join today for your annual tune-up, priority service, and member repair savings.
With the springs working right, it should lift with steady, moderate effort and stay put at about waist height. If you have to strain, the springs likely need attention.
Stiffness usually comes from friction, not weight. Dry hinges, worn rollers that slide instead of turning, or a dented track can make the door drag or stick at one spot. Lubricating the hinges and roller bearings often helps.
A dented track section, a worn roller or a dry hinge at that point is the usual cause. Look along the track from the side and lubricate the hinges and rollers. If it still catches, have a professional check the track.
It helps if the door is stiff from dry hinges or rollers. It won't fix heavy lifting caused by weak or broken springs.