Preheat your oven to 400°F (200°C) or prepare your air fryer to 400°F (200°C).
If your bread isn't already cubed, cut it into 1-inch cubes.
In a bowl, toss the bread cubes with the olive oil until evenly coated.
Add the garlic herb seasoning to the bread cubes and toss again to make sure everything is well combined.
Spread the seasoned bread cubes in a single layer on a baking sheet lined with parchment paper. If using an air fryer, spread the cubes in a single layer in the basket.
Bake the croutons for 5-10 minutes, or until golden brown and crispy.
Cook for about 5 minutes, shaking the basket halfway through to ensure even browning. Keep a close eye on them as they can burn quickly in the air fryer.
Once golden brown and crispy, remove the croutons from the oven or air fryer and let them cool completely before storing.