Why do clear phone cases turn yellow, and can you fix it?

The short answer

Most clear cases contain a soft, bendy plastic called TPU (thermoplastic polyurethane). Over months of use, ultraviolet light, heat and the oils on your hands slowly break down and oxidize the outer layer of that plastic. The new compounds absorb blue light, so the case looks yellow, and later amber or brown.

Because the color change happens inside the material, not on top of it, washing removes dirt but not the yellow tint. Once a case has properly yellowed, the only real fix is a new case.

What speeds yellowing up

The same few things come up again and again: light, heat and skin contact. A phone that lives on a sunny car dashboard or a windowsill will tint far faster than one kept in a bag.

• Sunlight and other UV light, the biggest single cause
• Heat: car dashboards, radiators, wireless chargers left running for hours
• Skin oils, sunscreen, hand cream and make-up rubbed into the edges
• Dye transfer from jeans pockets and colored bags
• Time: even a well-kept clear case changes slowly with age

Is it dirt or is it yellowing?

Take the phone out and look at the case against a sheet of white paper. Gray or patchy marks that sit on the surface, especially around the buttons and corners, are usually grime and will wipe off. An even yellow or amber tint across the whole soft frame, including places your fingers never touch, is the plastic itself changing.

How to clean a clear case without making it worse

Apple's own guidance for silicone, clear, polycarbonate and TPU cases is simple: take the phone out and wipe the case inside and out with a soft, slightly damp, lint-free cloth. It also lists what not to use: window cleaners, household cleaners, aerosol sprays, solvents, ammonia, abrasives and cleaners containing hydrogen peroxide (Apple: How to clean your Apple products).

That rules out most of the popular yellowing hacks. Bleach, peroxide soaks and baking-soda scrubs can scratch the surface, cloud the plastic or damage a printed design, and they still can't put back what UV light has changed. Let the case dry fully before you put the phone back in.

There is more on everyday cleaning, including printed and silicone cases, in our guide to cleaning a phone case.

How to keep a clear case clearer for longer

You can't stop yellowing completely, but you can slow it down noticeably.

• Keep the phone out of direct sun, especially on car dashboards
• Don't leave it on a hot charger or under a pillow while charging
• Wipe the edges with a damp cloth every week or two so oils don't build up
• Let hand cream and sunscreen dry before picking up the phone
• Avoid tight pockets in new dark denim

Clear cases at YOONIG

Our Clear build has a clear polycarbonate back with soft, clear TPU sides, and the design is printed on the back so the phone's own color shows through around it. Like any soft TPU, the sides can tint over a long time; the care tips above apply to them too.

If you would rather not see yellowing at all, an opaque build such as Slim or Tough hides the effect, because the print covers the whole back. You can compare every build in our case type guide or browse phone cases.

Frequently asked questions