Turn off the water supply to the toilet
Flush the toilet to empty the tank and bowl
Check the fill valve for leaks and replace it if needed
Inspect the flapper for wear, cracks, or poor sealing
Clean the flapper seat and flush valve opening
Adjust or replace the flapper chain if it is too tight or too loose
Check the tank bolts, washers, and gaskets for leaks
Tighten loose tank hardware carefully
Replace worn tank-to-bowl or supply line washers
Inspect the overflow tube for cracks or overflow issues
Adjust the water level to the correct mark
Replace the fill valve if the toilet keeps running or dripping
Replace the flapper if water still leaks into the bowl
Turn the water back on and test for leaks
Call a plumber if the leak continues or parts are damaged