
Samsung Galaxy S 3 LTE (Sprint)
The latest firmware for Samsung Galaxy S 3 LTE (Sprint) (SPH-L710) is L710VPUDNJ2 with Android 4.4.2 (KitKat), released on October 15, 2014 for 1 region (CSC). Every official firmware build for SPH-L710, 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/L710VPUDNJ2
All 4 builds in our database run Android 4.4.2 (KitKat). The newest build, L710VPUDNJ2, was released on October 15, 2014. No new build has appeared for 146 months, so regular updates for this model have most likely ended.

SPH-M840

SPH-L900

SPH-L710T

SPH-L720T

SPH-L720

SPH-L600

SPH-L520
The newest firmware for SPH-L710 runs Android 4.4.2 (KitKat): build L710VPUDNJ2, released on October 15, 2014.
The latest build for SPH-L710, L710VPUDNJ2, was released on October 15, 2014 (12 years ago).
SPH-L710 has had no new firmware for 146 months, so regular updates have most likely ended.
Yes, all firmware files for SPH-L710 are 100% official, original, and obtained directly from Samsung servers.
To flash SPH-L710, 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 SPH-L710.