Adjust the cooking rack to the bottom placement and preheat toaster oven to 350°F on the BAKE setting.
Using a serrated knife, slice bagel width-wise into 1/4-inch thick pieces. Stack pieces and slice in half down the middle.
Add bagel slices to a medium bowl. Drizzle with oil and season generously with salt. Toss well to combine and coat all of the pieces.
Arrange bagel pieces in a single layer on an ungreased baking sheet.
Bake for 10 minutes. Carefully remove the hot pan and flip the bagel pieces. Continue baking until the chips are browned and crisp, about 5 to 8 minutes.
Allow chips to cool completely on pan before storing in a sealed container.
Convection Toaster Ovens - Reduce temperature to 325°F. Flip chips after 8 minutes of cooking. Continue baking until browned, about 3 to 5 minutes.
Air Fryer Toaster Ovens - Do not preheat oven and use air fryer basket instead of baking sheet. Reduce temperature to 300°F and select the Air Fry Function. Cook for 5 minutes, flip chips and continue cooking for 1 to 2 minutes or until golden and crispy.
The number of servings will depend on the size of the bagel and your appetite. A bagel weighing 3 ounces makes about 1½ cups of bagel chips.