These can be some possible reasons why your aloe vera leaves are turning brown.
Aloe vera plants do well grow in direct sunlight, but sometimes too much light can damage your aloe's leaves. Plants grown in very hot sunlight can become sunburned, leading to browning. This is especially common with plants that have been moved from a shadier location to a very sunny one suddenly, with no adjustment period. If you plan on moving your indoor aloe outdoors, you'll need to start with a shady spot and gradually transition the plant to a sunnier spot. To deal with sunburned aloe plants, simply move them into a spot with more shade and diffuse light.
Aloe vera plants are sensitive to sudden changes in temperature. When the weather becomes cold and wet, move your potted aloe vera inside; otherwise, it could start to brown and die. Ideally, the temperature for these plants shouldn't dip below 50 degrees Fahrenheit.
Known for their ability to store water within their leaves, aloe plants do not need frequent watering. In fact, overwatering your aloe can lead to root rot and browning. This is especially true for potted aloe plants that don't have proper drainage holes. To prevent browned leaves due to overwatering, water your aloe only when the soil has completely dried out. When you do water the plant, do so thoroughly so you soak the soil.