There are a few different products that can be used to seal a garage floor. The best garage sealer for your application depends on what you want the floor to look like once sealed, and how you need the sealer to perform.

Here is a list of the best concrete sealers for garage floors:

1. Silicate: Silicate sealers are used to increase the surface strength of the concrete. They should be used for no other purpose other than that. Silicates will not change the look or color of the concrete and work entirely below the surface.
2. Silane-Siloxanes: Silane-Siloxane sealers are water repellent sealers. Water repellent sealers will cause water and other liquids to bead off the surface. They help with salt stains, mold and mildew, and spalling but they will not stop oil or gas from staining the concrete. Silane-Siloxane sealers will not change the look or color of the concrete and work entirely below the surface.
3. Aliphatic Polyurethane Coatings: This type of coating will form a film over the surface of the concrete. Some coatings, like the Armor UTN60 (shown below), come with additives making the coating scratch and abrasion resistant, chemical and acid resistant, oil and gas resistant. This category of coating is used in residential and industrial applications.
4. Epoxy Coatings: Epoxy coatings are very inexpensive and easy to come by. They won’t be as durable, or last as long as an aliphatic but they will provide a few good years of service.

Picture taken from FoundationArmor.com:

How To Apply Foundation Armor UTN60 Garage Floor Coating