TeraCopy

Description

Windows Explorer copies files from one location to another and most of the time that’s all we need to do. But when copy job contains thousands of files, takes hours to complete, and stops completely when it hits one file with an error, the limitations become real. TeraCopy addresses exactly that: it is faster than the Windows built-in handler to copy and move files, it verifies the integrity of each file transferred using checksum comparison, it skips files that cause errors, but does not stop the entire job, and it allows users to review all errors and retry individual files at the end.

Code Sector is a Ukrainian software company that released TeraCopy in 2007 as a replacement for the copy dialog in Windows Explorer. The free version takes care of core transfer, skipping errors, and checking the checksum. TeraCopy Pro includes folder favorites, a file list export feature, and Shell extension integration with TeraCopy routing all Explorer copy/move operations through TeraCopy automatically.

ORIGINS AND DEVELOPMENT

Windows Vista’s file copying was notoriously unreliable for large transfer jobs — the time remaining estimate was famously inaccurate, operations paused were broken in early versions, and error handling stopped entire jobs for single bad files. TeraCopy was launched into that environment and found an audience right away among users transferring large libraries of media, backups, and project archives between drives.

Code Sector improved TeraCopy significantly throughout the 3.x generation, redesigning the interface and integrating checksum verification into the standard process, rather than as a separate manual step. The macOS version was released later, as a port of the same functionality to Apple hardware, but the Windows version is the more fully developed of the two.

The software was on lists of critical Windows utilities for years, recommended by tech publications and power users who regularly moved large amounts of data between drives, NAS devices and external storage. The one-time purchase price for Pro meant it could be used without a subscription commitment.

KEY FEATURES

Verified File Transfer

Every file TeraCopy copies gets a checksum — a hash value calculated from the file’s contents — before transfer and again after transfer is complete. This comparison of the pre- and post-transfer checksums ensures that the copied file is bit-for-bit identical to the original. If the checksums don’t match, TeraCopy records the file as failed and gives you a retry. This verification step helps to catch storage errors, bad cables and drive failures that would otherwise result in silently corrupted copies.

Error Handling

When TeraCopy finds a file that it cannot copy – a locked file, a file with read errors on a failing drive, a permissions issue – it logs the error and continues on with the rest of the transfer queue. At the end of the job the error log contains all the failed files and their error code. Users can retry failed files, skip files, or copy the list of errors to the clipboard. This behavior is different from Windows Explorer which stops the whole copy operation when it encounters a single error.

Transfer Speed

TeraCopy optimizes the copy pipeline for sustained transfer rates on large sets of files. It uses asynchronous copying which overlaps the reading of the next file with the writing of the previous one, minimizing the idle time between file completions. For sequential transfers of a large number of small files — a common bottleneck since each file will require separate filesystem operations — the buffering approach of TeraCopy improves throughput over the Explorer handler.

Pause and Resume

Long transfer jobs have the opportunity to stop and resume at any point. Pausing releases the files involved so that they can be used by other applications, and resuming picks up where the pause occurred. This makes TeraCopy practical for transfers that need to run in the background while the machine is still usable.

File List Management

Before initiating a transfer, TeraCopy displays the complete list of the queued files with source paths, destination paths and file sizes. Users can delete single files from the queue before beginning or add more files to an existing job. After transfer is completed, the list is updated with the status of each file: copied, verified, skipped or failed.

Windows Shell Integration (Pro)

TeraCopy Pro is part of the right click context menu and file copy dialog of Windows Explorer. Copy or move operations initiated via Explorer go through TeraCopy automatically instead of the Windows built-in handler. The integration can be turned off when the default Windows handler is desired.

Checksum Algorithms

Verification with selectable hash algorithms including CRC32, MD5, SHA-1, SHA-256 and SHA-512. Users that need to verify files against externally-provided checksums — comparing a downloaded ISO against a publisher-provided hash — can import a checksum file and TeraCopy verifies each file against its listed value.

SYSTEM REQUIREMENTS

• Windows: Windows 7, 8, 10 or 11 (32 and 64 Bit)
• macOS: macOS 10.13 High Sierra or later
• Storage: 25MB installation footprint
• Note: TeraCopy Pro is one-time purchase; Free version with core functionality intact