BootUpdater
Local in-browser processing / v0.1

Update Android boot images from incremental OTAs.

Generate verified new partition images directly in your browser before updating.

Source files

Reconstruction inputs
01
Drop current stock .img here or browse file Raw, unmodified image from your current firmware · up to 256 MiB
Incremental OTA package 02
Drop the incremental OTA ZIP here or browse file Official A/B incremental OTA ZIP containing payload.bin · up to 2 GiB

Status

Ready
Waiting for source files0%

Select your current boot image and its matching incremental OTA to begin.

  1. Inspect OTA manifestWaiting
  2. Verify current imageWaiting
  3. Apply incremental patchWaiting
  4. Verify updated imageWaiting
Activity log 0 events
  1. Activity events will appear here.

Files are processed on your device using WebAssembly, not uploaded to a server. Keep this tab open until you save the result.

How it works & FAQ

What does this tool do and why do I need it?

When an Android phone receives an incremental OTA update, the update package only contains differential patches (binary deltas), not full partition images like boot.img or init_boot.img. If you are rooted (Magisk, KernelSU, APatch) and need the new boot image to maintain root after updating, or if you need the updated kernel without downloading a 4–6 GB full factory ROM, BootUpdater applies the incremental OTA patch to your current stock image and generates the exact new boot image right in your browser.

What files do I need to provide?

You need two things: 1) The unmodified stock partition image (.img) from the firmware currently installed on your phone (if rooted, use the original stock image backup, not the Magisk-patched one). 2) The matching incremental OTA update ZIP (or direct download link) for your device.

Which partitions and operations are supported?

Supports raw boot, init_boot, vendor_boot, dtbo, recovery, and vbmeta partition images up to 256 MiB, and incremental A/B OTA ZIPs up to 2 GiB. Supported patch operations: SOURCE_COPY, REPLACE, REPLACE_BZ, REPLACE_XZ, SOURCE_BSDIFF, BROTLI_BSDIFF, ZERO, and DISCARD. (ZIP64, compressed payload.bin entries, full OTAs, PUFFDIFF, ZUCCHINI, and LZ4DIFF are rejected).

What does “verified” mean?

BootUpdater calculates the SHA-256 hash of your source image to ensure it matches what the OTA expects. After applying all delta operations, it verifies that the output image's SHA-256 matches the target hash specified in the official Android payload manifest. This guarantees bit-for-bit exact reconstruction identical to what the OTA installer on the device would have produced.

Why can a direct link fail?

A direct link can fail if the URL has expired, is private, or cannot be reached. In that case, download the OTA ZIP directly to your device and choose Local ZIP.

Memory, privacy and device safety

A desktop browser is recommended. Image processing runs in WebAssembly and uses device memory; large operations may exceed a phone's memory. There are no accounts, analytics, or server-side file storage. BootUpdater never connects to your device and never flashes anything.