Disk Drill can recover plain text TXT files with two of its recovery methods: Undelete Protected Data and Quick Scan. Undelete Protected Data can only be used with Recovery Vault and Guaranteed Recovery, Disk Drill’s data protection features, and they have to be enabled prior to data loss. If you did not have data protection enabled, then Quick Scan is your only hope for plain text file recovery. It works well if you use it immediately after data loss occurs.
Quick Scan chances are better on the FAT and NTFS file systems, which are used mainly on non-Mac operating systems (such as Windows), and are used on most USB flash drives: these file systems keep a large amount of file-related data, which Disk Drill can use to find even plain text files. So if you are recovering plain text from a FAT- or NTFS-formatted disk, you are (probably) in luck. If you are recovering from a Mac internal drive, however, chances are extremely high that your file system is HFS+. Unlike FAT and NTFS, HFS+ does not keep a large amount of catalog information about deleted plain text files. To have any luck with an HFS+ volume, you must scan it with Quick Scan very soon after the data is lost.
Usually Deep Scan is the best option for severe data loss situations. Unfortunately, Deep Scan cannot pinpoint and rescue plain text files. This is because of the nature of plain text files. To find files on a hard drive, when there is limited information about where file fragments are located, Disk Drill (or any other recovery program) relies on signature analysis. Disk Drill knows how a QuickTime movie, for example, “should” look and can arrange the fragments it finds like the pieces of a jigsaw puzzle.
But with text files, these techniques are of no use. Plain text files are, well, plain: they don’t have the distinctive file structure that other file types do. So these files do not give clues as to which pieces fit where, or where the file begins and ends. So Deep Scan isn’t able to recognize or combine the pieces of text files that it may find on a hard drive.