Windows App

Verified File Transfer Tool for Windows

ZB Transfer is a Windows file transfer tool that copies files and verifies the result with BLAKE3 hashing. Use it to move large folders, compare source and destination folders, resume interrupted transfers, and confirm that backups are identical.

Features

Copy files and verify every byte

Copies files then verifies each one using BLAKE3 hashing. The job only completes when every file is mathematically confirmed identical to the source.

Compare folders before or after transfer

Check two folders for differences without copying anything. Fast mode uses file size and date; BLAKE3 mode does full content verification.

Resume interrupted file transfers

Interrupted transfers can be resumed exactly where they left off. No need to restart a large job from scratch after a disconnection or shutdown.

Real-time Progress

Live transfer speed, ETA, and per-file status as the job runs. Detailed activity log for every operation so you know exactly what happened.

Skip Existing Files

Option to skip files that already exist at the destination. Useful for incremental backups or topping up a partially complete transfer.

500–800 MB/s

Optimised with 8 MB chunk sizes for maximum throughput. Typical SSD speeds of 500–800 MB/s — competitive with native Windows copy.

ZB Transfer vs normal Windows copy

Normal copy tools move files but do not always prove the destination matches the source. ZB Transfer verifies copied files with BLAKE3 hashing so you can confirm that every byte arrived correctly.

Manual

System Requirements & Installation

Requires: Windows 10 or later, x64 processor, 100 MB disk space.

Install from Microsoft Store.

Copy & Verify (Recommended)
  1. Launch ZB Transfer.
  2. Click Select Source and choose your source folder.
  3. Click Select Destination and choose where to copy.
  4. Select Copy + Verify mode.
  5. Click Start Transfer.

ZB Transfer scans the source, copies files in 8 MB chunks, computes BLAKE3 hashes during copy, then compares source and destination hashes. The job only reports success when all hashes match.

Compare Mode

Use Compare to check two folders for differences without copying anything.

  • Fast — checks file size and modification date. Very quick but does not detect content-level corruption.
  • BLAKE3 — full content verification. Slower but detects any difference, including silent corruption.

Results show missing files per folder. You can optionally copy selected missing files to the destination from the results view.

Resuming an Interrupted Transfer

If a transfer is interrupted (power loss, disconnection, manual stop), reopen ZB Transfer with the same source and destination. Enable Skip Existing and select Copy + Verify.

ZB Transfer will skip files already present at the destination and continue with the remaining files. Files that were partially written will be re-copied and verified.

Understanding Results

Successful transfer: All files copied and all BLAKE3 hashes matched. Your destination is a verified identical copy of the source.

Verification failure: One or more files did not match. ZB Transfer lists the affected files. Re-run the transfer for those files or investigate the drive for errors.

The activity log records every file operation. Access it from the results panel after the job completes.

Frequently asked questions

What does verified file transfer mean?

It means the app checks that the destination files match the source files after copying, instead of only assuming the copy succeeded.

How does BLAKE3 verification work?

ZB Transfer calculates a BLAKE3 hash for files and compares source and destination results to detect any mismatch.

Can ZB Transfer resume interrupted transfers?

Yes. Use the same source and destination and enable skip existing files to continue a partially completed job.

Can it compare two folders without copying?

Yes. Compare mode can check two folders and show differences without starting a copy operation.

Is it useful for backups?

Yes. It is useful when you want to confirm that backup folders, external drives, or archive copies are identical.