NTFSTool Drive Helper

Check a folder before copying it between Mac and Windows drives. Finds names and sizes that NTFS, exFAT or FAT32 can't store.

NTFSTool Drive Helper checks a folder before you copy it to an external drive, so you find problems first instead of halfway through a copy. How it works 1. Choose a folder, or drop one onto the page. 2. Pick the format of the drive you are copying to: NTFS, exFAT or FAT32. 3. The extension lists every file that would fail or cause trouble, with the reason. What it checks • Characters not allowed in file names ( < > : " \ | ? * ) • Names Windows reserves (CON, NUL, COM1 and similar) • Names ending in a dot or a space • File names over 255 characters, and paths over 259 • Single files of 4 GB or more, which FAT32 cannot hold • Two names that differ only by letter case When a problem is found, it also tells you what to change: rename the file, or use a different drive format. Privacy Everything runs in your browser. The extension asks for no permissions, makes no network requests, reads only file names and sizes (never file contents), and keeps nothing after you close the page. Try it without any files using the "Try with sample files" button. Made by NTFSTool.