I just ordered the T-Mobile Samsung Galaxy Light. From looking at the dimensions of the phone, the length and width of the phone appear to be identical, but the depth has a 0.02" difference (the Light being the thinner of the two). As far as the rest of the phone goes, the Light has a 1.4 GHz quad-core processor versus the S3 Mini's 1.2GHz Dual–core, the Light can only handle up to a 32 gig SD card versus the S3 Mini taking up to a 64 Gig and the one thing that's a little harder to measure (due to how it's stated on T-mobile's vs. Verizon's websites) "Talk Time" on the Light is "12.5 hours (19.16 days standby)" versus the S3 Mini's "Usage Time" at "up to 19 hours (11.6 days standby)". They both have Android 4.2.2 Jelly Bean, 5MP Rear-facing camera, AF with LED Flash and VGA Front-racing camera, NFC capabilities and 4G LTE. For the purposes of ordering a protective case on my phone, I just went ahead and ordered one that is supposed to fit the S3 Mini since I don't see much out there for the Light and I can't see 0.02" causing that big of an issue on the fit of the case, though we'll see when I receive both the phone and the case in a few days. Screen protectors should seemingly fit just fine as the dimensions in that aspect appear to be the same. Hopefully all of that info helps you.