To save tomato seeds, let the tomato ripen on the vine until it is soft with lots of light spots.
Cut the tomato in half and remove the pulp, then put it into a container or jar with about an inch of water.
Now wait for the plants to turn into fruit with tomatoes that are orange. Once they have turned color discard any green tomatoes.
Next cut off the stem end of each tomato and store them in a cool, dry place for up to a year.
So this is how to save tomato seeds.