Hard pedal

Easy way to find out. Get out on a lightly used road, do a couple of stops "normally" to see what you have, then make a couple of stops with the car in neutral, engine off!! Same pedal pressure? Bad booster.

Also, idle car, stopped. Shut off engine, apply brakes "lightly" a couple of times. Then pump several times to be sure vacuum depleted, then reapply brakes "same as" you did at first. If there's no real change in "pedal feel" ==bad booster.

Apply pedal with vacuum depleted, lightly. Start car at idle, if you do NOT feel pedal "try to go down" a bit due to boost == bad booster.