
Samsung Galaxy Tab3 8.0
The latest firmware for Samsung Galaxy Tab3 8.0 (SM-T315T) is T315TDVUBOL1 with Android 4.4.2 (Jelly), released on December 6, 2015 for 1 region (CSC). Every official firmware build for SM-T315T, newest first: one row per build with all regions (CSC) that received it.
Each firmware build has its own page at https://samfirm.shop/build/{PDA}, where {PDA} is the build number from the list above. Example: https://samfirm.shop/build/T315TDVUBOL1
All 3 builds in our database run Android 4.4.2 (Jelly). The newest build, T315TDVUBOL1, was released on December 6, 2015. No new build has appeared for 132 months, so regular updates for this model have most likely ended.
Specifications of SM-T315, a regional variant of the same device. Chipset and SIM lines are left out: they can differ by region.

SM-T315

SM-T310

SM-T210L

SM-T320X

SM-T321
The newest firmware for SM-T315T runs Android 4.4.2 (Jelly): build T315TDVUBOL1, released on December 6, 2015.
The latest build for SM-T315T, T315TDVUBOL1, was released on December 6, 2015 (10 years ago).
SM-T315T has had no new firmware for 132 months, so regular updates have most likely ended.
Yes, all firmware files for SM-T315T are 100% official, original, and obtained directly from Samsung servers.
To flash SM-T315T, you need to download the appropriate firmware, put your device into Download Mode, and use the Odin tool to load the BL, AP, CP, and CSC files.
Downgrading is only possible if the bootloader version (binary bit) of the old firmware matches the current one. Always check the binary version before flashing SM-T315T.