Clear a blocked toilet with a flange plunger, and use an auger for stubborn clogs without overflowing the bowl.
If the water is rising, remove the tank lid and push the flapper down to close it, or turn the shutoff valve behind the toilet clockwise to cut the water supply.
Choose a plunger with an extended rubber flange. Insert it so the flange seals the drain hole and there's enough water to cover the cup. Push down gently first to expel air, then plunge firmly 15 to 20 times.
If plunging alone fails, pour a squirt of dish soap and a bucket of hot (not boiling) water into the bowl, wait 10 to 15 minutes to let it break down the blockage, then plunge again.
For stubborn blockages, insert a toilet auger (closet auger) into the drain, crank the handle to feed the cable, and rotate to hook or break up the obstruction, then pull it back out.
Once the water drains freely, flush once and watch the bowl empty and refill normally. If it backs up again, stop and avoid repeated flushing to prevent overflow.