Whether you use a cheap plastic screen protector or a pricy glass cover, air bubbles can crop up after installation, obscuring the display and making touch gestures harder to execute. The best cure for air bubbles is prevention — applying the protector perfectly the first time — but you don't need to live with a lumpy screen. Try to work out the bubbles or, if necessary, pull the protector off and start over.
Plastic Screen Protectors
Cheap screen protectors are made of a thin, bendable plastic that sticks to your phone's screen. These protectors are the most susceptible to air bubbles, but also the easiest to adjust after application. Bubbles under plastic protectors form due to uneven application or from an imperfect seal around the edges.
Use the edge of a credit card — or the application tool, if your screen protector included one — to gently push the air bubble toward the nearest edge, pressing the protector flat behind the bubble as the tool moves.
When the bubble reaches the edge of the phone, slightly peel up the side of the protector to release the air if the bubble doesn't flow out on its own. Once the air has an escape route, continue pressing the bubble outward, flattening the protector with the credit card all the way to the edge.
If you can't get the bubbles out or if the protector ends up out of place, you'll have to start over from scratch. Peel off the protector and clean the phone's screen. If you want to reuse the same protector, clean it as well before reapplying it. A used screen protector never sticks as well the second time, however, so consider replacing it with a new one. Thankfully, plastic protectors don't cost much and often come in packs of two or more protectors.
Wet-Apply Screen Protectors
Some screen protectors use soapy water to help attach the plastic to the screen. Other than the initial setup, however, these protectors work much like their dry counterparts. If bubbles crop up, try to push them out with a credit card, but you might have more trouble getting the protector to readhere to the screen. If you only have trouble around the edge, try adding more water to the underside of protector, pressing it down and squeegeeing it with a card out to get the protector to stick. For larger problems, however, you'll need to take the entire protector off and reapply it.
Glass Screen Protectors
High-end screen protectors use tempered glass instead of plastic, retaining the phone screen's natural hardness. Glass protectors aren't as flexible as plastic protectors, and they press on flat, covering the entire screen at once. Both of these factors help prevent air bubbles, but bubbles can still crop up if the protector doesn't attach securely.
Try to gently peel up the protector near the bubble. If air is getting in, the protector is probably weakly attached, so you should be able to pull it up without too much effort. Clean under the poorly attached area with the corner of a lint-free cloth, and then press the protector back on, pushing from the center of the phone outward.