Why convert BACKUP1 to IMG?
People recombine the split parts into one .img so they can mount the raw ext4 image, browse the filesystem, or flash it back to a device. On its own a single .backup1 part is useless because it is only the middle of one continuous image.
How to convert BACKUP1 to IMG
cat (coreutils) FREE
Join the parts in order: cat userdata.backup userdata.backup1 userdata.backup2 > userdata.img. Run it on a filesystem that allows files over 2GB (ext4, NTFS).
dd (coreutils) OPEN-SOURCE
If each part has a 512-byte header, skip it while appending: dd if=userdata.backup1 skip=512 iflag=skip_bytes oflag=append conv=notrunc of=userdata.img, repeating per part.
About these formats
A .backup1 file is the second part of a split backup created by an Android phone or tablet in System Recovery Mode. When the userdata backup is larger than about 2GB, the recovery splits it…
Open .BACKUP1 details →
.IMG
Raw Disk/Disc Image
An IMG file is most often a raw, sector-by-sector copy of a CD/DVD, floppy, USB stick, or partition -- frequently identical to an ISO file. On Windows 8 and later, right-click and choose…
Open .IMG details →Quality & what to watch
- The parts must be concatenated in exact order; a missing or out-of-sequence chunk corrupts the whole image.
- Some device backups prepend a 512-byte header to each part - leaving it in produces a broken filesystem, so use
ddto strip it. - The result is a raw block image, not a compressed archive; it will be the full size of the original partition even if mostly empty.
Frequently asked questions
Do I need all the `.backup` parts?
.backup, .backup1, .backup2 and any further parts are one image split up; you must join every piece in order.Why does my joined image look corrupt?
dd skipping the first 512 bytes of every part instead of a plain cat.Can I do this on Windows?
copy /b part1+part2 out.img in cmd, but do it on an NTFS drive so the file can exceed 2GB.
