Open boot.img files in your browser
The kernel and ramdisk an Android phone starts from, the image people patch to root a phone. Look inside a boot.img, init_boot.img or vendor_boot.img right here. Nothing leaves your device.
Or drop it anywhere on this page
What you'll see
Your boot image opens on a page of what it holds, with its ramdisks' files listed like a folder.
- The kernel • Its version, compiler and command line
- Ramdisks • Every file, packed with gzip or LZ4
- Verified boot • Its signature and hash checked
- Device trees • Each opens as its source
About boot.img
Every Android phone since the first, in 2008, starts from a boot image: the Linux kernel and the ramdisk it runs first, behind a header that starts with ANDROID!. Android 11 moved the phone maker's part into vendor_boot.img and Android 13 the generic ramdisk into init_boot.img, and rooting a phone with Magisk means patching one of them, so they're the images people take out of updates most.
The header, in versions 0 to 4, gives each part's size, the Android version and security patch it's for and the kernel's command line. The kernel is often packed with gzip or LZ4, the ramdisk is a CPIO archive packed with gzip or LZ4, and a vendor boot image can hold several ramdisks and the device trees. Many end with verified boot's footer, which keeps the image's hash and a signature.
Filepeek reads the header and the kernel's version and compiler, lists each ramdisk's files as a folder, opens the device trees as their source and checks the footer: the signature against the key it carries and the image against its hash. vbmeta.img lists every partition it vouches for, with their hashes and the keys that sign the rest.
Android boot image
.img
Format
- MIME type
- application/octet-stream
- Made by
- Google's mkbootimg
- Released
- 2008
Inside the file
- Kernel
- Linux, packed or not
- Ramdisk
- CPIO, with gzip or LZ4
- Header
- Versions 0 to 4
- Signed
- Verified boot's footer
Opens in every browser
Filepeek opens boot images in Chrome, Edge, Firefox and Safari, on any computer or phone. On their own, browsers only download them.
- YouChromeOpens through Filepeek
- YouEdgeOpens through Filepeek
- YouFirefoxOpens through Filepeek
- YouSafariOpens through Filepeek
Apps that open boot.img
- WindowsAndroid Image Kitchen, free
- Macunpack_bootimg from Android's source, in Terminal
- iPhone and iPadNo app reads it
- AndroidMagisk patches it to root the phone
Questions
How do I see what's in boot.img?
Drop it on this page. The kernel's version, the Android version, its security patch and the command line show at once, and the ramdisk opens as a folder of its files.
Should I patch boot.img or init_boot.img?
Phones that launched with Android 13 or later keep the generic ramdisk in init_boot.img, which is the one Magisk patches, while older ones keep it in boot.img. If boot.img shows no ramdisk here, patch init_boot.img.
Does it check the signature?
Yes. The footer's signature is checked against the public key it carries, and the image against the hash it keeps. Whether a phone trusts that key is up to its bootloader.
What is vbmeta.img?
Verified boot's table of contents: the hash of each partition it vouches for and the keys that sign the others. It opens here as that list, with its own signature checked.
Where do I get boot.img?
From your phone's factory image or full update. Its payload.bin opens here too, and boot is one of its partitions.