Boot.img.lz4 Jun 2026

: LZ4 is a lossless compression algorithm optimized for extreme speed. It can reach decompression speeds of several gigabytes per second, often limited only by the RAM's speed.

You likely decompressed an LZ4 file that was not a full boot image—perhaps only a kernel or a DTB. Check the source.

# Using magiskboot (from Magisk) magiskboot unpack boot.img boot.img.lz4

Do not rely solely on the extension. Use the file command on Linux/macOS or inspect the magic bytes.

The -d flag stands for decompress. You will see an output size roughly 2-4x larger than the original. : LZ4 is a lossless compression algorithm optimized

$ xxd boot.img.lz4 | head -n 2 00000000: 0422 4d18 6440 2065 6e00 0000 0000 0000 ."M.d@ en.......

: This indicates high-speed compression. Manufacturers like Samsung use LZ4 because it allows the device to decompress the kernel extremely fast during power-up, reducing overall boot time. Why You Need the boot.img.lz4 File Check the source

lz4 -d boot.img.lz4 boot.img fastboot flash boot boot.img