Disk Drill vs GNU ddrescue

Disk Drill scans storage devices to find and recover deleted, lost, or damaged files. It runs on macOS 10.15 or later and Windows 10 or later, and supports internal and external drives, SSDs, USB drives, memory cards, cameras, RAID arrays, virtual disks, and disk images. The free Basic edition scans storage and previews recoverable files; Windows users can recover up to 100 MB without upgrading. PRO provides unlimited data recovery and recovery methods including Quick & Deep Scan and Lost Partition Search. It also covers both supported operating systems under one license, with activation on up to three devices by one user. The free edition includes Recovery Vault metadata protection and byte-level backups. PRO costs $89 a year for an annual subscription or $149 as a one-time purchase for a lifetime license. PRO is for personal use, while Enterprise is listed for multiple users and includes priority technical support and forensic data export. PRO purchases are non-refundable except where consumer protection laws require refunds.

GNU ddrescue copies data from a file or block device to another location, prioritizing readable areas when read errors arise. Its basic recovery process is automatic, so it does not require stopping and restarting at every error. A mapfile records progress; an interrupted job can resume and reread only blocks that still need attention. The algorithm handles good areas first and defers bad or slow ones to reduce unnecessary drive movement. It works with kernel-supported devices, including ATA, SATA, SCSI, floppy disks, and flash media cards, and can use direct disc access where supported. Fill and generate modes provide additional ways to write selected output areas or create an approximate mapfile from an input and partial copy. The package includes ddrescuelog for manipulating and comparing mapfiles and checking rescue status. GNU ddrescue is free software under the GNU General Public License, version 2 or later, with no paid plans stated. POSIX systems are recommended; the manual discusses Cygwin but warns of potentially misleading permission errors. A device or partition used as the destination will have its data overwritten. Because ddrescue needs random access, create an uncompressed image before compressing it.