Tempered glass for flat phone and tablet screens: it feels like the real screen and can crack in place of the display. TPU film for curved screens, watches and anything that folds. PET film only if all you want is scratch protection at the lowest price.
The five materials compared
| Material | Protects against | Feel | Best for | Weak point |
|---|---|---|---|---|
| Tempered glass | Scratches, some impact | Like the bare screen | Flat phones and tablets | Cracks (by design); edges can chip |
| PET film | Light scratches | Plasticky, slightly draggy | Budget, e-readers | No impact protection; scratches itself |
| TPU film | Scratches, minor scuffs | Soft, slightly rubbery | Curved screens, watches, foldables | Can look wavy; tricky wet install |
| Hybrid / "nano" glass | Scratches, light knocks | Close to glass | Curved-edge phones | Less impact absorption than tempered |
| UV liquid glass | Scratches, some impact | Like glass | Curved-edge phones | Messy to fit; UV glue can seep |
Tempered glass: the default for most people
Tempered glass is heat-treated so that when it breaks, it breaks in a way that spreads out the energy of an impact. That's the real reason to use it. A cracked protector over an intact screen means it did its job. It also feels like the phone's own screen, so swipes and the oleophobic smear-resistant coating behave as you'd expect.
Its limit is the shape. Glass can't bend, so on curved screens it either stops short of the curve or lifts off it. Most current phones have flat screens, so this matters less than it did a few years ago. See curved screens if yours isn't flat.
PET film: cheap scratch protection
PET is the thin, clear plastic that ships in cheap multipacks. It stops keys and coins scratching the glass underneath, and that's about it: it has no meaningful impact protection. It scratches easily itself, and it feels less smooth than glass. It's still a reasonable choice for e-readers and tablets that live indoors.
TPU film: for anything that curves or folds
TPU is softer and stretchier than PET. It can wrap round curved edges and flex with folding screens, and small scratches in it tend to fade. The catch is appearance: some TPU films show a faint "orange peel" texture, and many are fitted wet with a spray solution, which is fiddlier than dry glass. It's the right material for smartwatches and folding inner screens where the maker allows a film.
Hybrid and liquid glass
"Hybrid" or "nano" glass is a thin, flexible glass-and-polymer laminate: it feels better than film but gives up some impact protection. UV liquid glass, like Whitestone's Dome system, uses a liquid adhesive cured under a UV lamp. It fills curved edges completely, but fitting it is messy, and on some phones the liquid can seep into speaker grilles. We only suggest it for curved-edge phones.
Decide by device
| Device | Material |
|---|---|
| Flat-screen phone | Tempered glass |
| Curved-edge phone | UV liquid glass, hybrid glass or TPU |
| Foldable inner screen | Keep the maker's factory film |
| Foldable cover screen | Tempered glass |
| Tablet for video | Tempered glass |
| Tablet for handwriting | Paper-feel film |
| Watch | TPU film or a bumper cover |
Questions people ask
Is tempered glass better than a plastic screen protector?
For flat phones and tablets, yes: it feels like the screen and absorbs some impact. Plastic films are better for curved or folding screens and watches.
Does a cracked tempered glass protector mean it worked?
Often, yes. The glass took energy that would otherwise have reached the display. Replace it promptly so grit can't work through the cracks.