Hash. Compare.
Trust your backups.

Generate sha256sum-format manifests of entire directory trees. Compare two folders, two manifests, or one of each — differences appear live as the scan runs.

GET IT ON Google Play See it in action ↓

Offline · no internet permission
Standard sha256sum format
Pause & resume long scans

Why this exists

You copied a folder to a USB drive. Did every byte make it?

A photographer ships an archive to a client. A sysadmin restores a backup. You drag a project to a new laptop. Without a checksum manifest you are hoping the copy was perfect — not knowing.

sha256sum walks an entire directory tree, computes a SHA-256 fingerprint for every file, and writes a manifest in the same one-line-per-file format used by the GNU coreutils tool of the same name. Compatible with Linux, macOS, BSDs, and Windows tools out of the box.

Two screens, one job

Built to do exactly two things well.

Hash a folder tree to a manifest file.

Pick a source folder and an output file. Tap Compute hashes. The app walks every subdirectory and writes one line per file in standard sha256sum format.

$ head -3 Sync3.sha256
3f9b4c…a1d  Photos/2025/Iceland/raw/DSC_5012.CR3
8c2e57…b4f  Photos/2025/Iceland/raw/DSC_5013.CR3
e0a611…29c  Photos/2025/Iceland/raw/DSC_5014.CR3

Live progress: files, bytes, speed, ETA
Pause & resume — survives screen-off
Foreground service with a persistent notification
Compatible with sha256sum -c on any UNIX

Hashing screen at 81% with progress, files, read, speed, and elapsed-time metrics

Compare anything. Live tree of differences.

Each side of the comparison can be a folder or an existing .sha256 manifest. Folder vs. folder, manifest vs. manifest, mixed — the workflow is identical.

← only on the left
→ only on the right
≠ exists on both but content differs

Differences appear as files are scanned — no waiting for the full pass
Tree view collapses equal subtrees so the screen shows only the news
Per-directory rollup counts of all three difference types
Pause & resume just like the hashing screen

Compare screen scanning a folder against a hash file, showing a live diff tree

Runs in the background. Tells you when it's done.

Long hashing jobs run as a foreground service so Android doesn't kill them. A live progress notification stays in the shade — pause, resume, or cancel without re-opening the app.

Survives screen-off, app-switch, and locked screen
Pause / Cancel directly from the notification
Storage Access Framework — pick from internal, SD card, USB-OTG, or any DocumentsProvider

Hash file successfully written confirmation screen

System notification showing hashing at 80% with Pause and Cancel actions

Who it's for

A tool for people who already think in checksums.

Photographers & videographers

Verify that a multi-hundred-gigabyte archive landed on the LTO, the NAS, the client SSD — byte-for-byte.

Backup-obsessed everyone

You wrote a backup script. You want proof, not faith. Hash the source, hash the destination, diff.

IT & sysadmins

Audit a deployment. Confirm an image was restored cleanly. Capture a manifest as evidence.

Developers

You already know sha256sum -c. This is the same tool, on Android, for trees of files.

Privacy

No accounts. No cloud. No telemetry.

The app does not request the INTERNET permission. It cannot phone home because it cannot reach a network at all. All file access goes through the Storage Access Framework — you explicitly pick every folder and file the app touches.

Read the full privacy policy →

✓ No internet permission
✓ No analytics or crash reporting
✓ No third-party SDKs
✓ No account, ever
✓ No ads
✓ Open-format output (works with GNU coreutils)

Install it. Hash a folder. Be sure.

GET IT ON Google Play

net.rygielski.sha256sum

Hash. Compare.Trust your backups.