OneDrive and Dropbox enforce specific rules for file and folder names to ensure reliable syncing across devices and operating systems. These limits primarily involve prohibited characters (like , /, :, *, ?, ", <, >, |), restrictions on leading/trailing spaces or periods, and a maximum path length (often around 255-260 characters total). Names are usually case-insensitive. While generally similar, minor restrictions can differ slightly between the platforms and underlying OS limitations (Windows vs. macOS).

For example, a file named Report: Project\ABC?2024.docx would likely fail to sync on either service because it contains the prohibited characters :\?. Similarly, creating a folder named .temp (starting with a period) within a deeply nested directory structure exceeding the path length limit might cause errors in Dropbox on Windows. These constraints apply universally to files synced via the desktop apps, mobile apps, or web interfaces.

These naming rules enhance platform compatibility and prevent sync conflicts. However, the maximum path length limit remains a common pain point, especially when syncing complex folder structures. Strict character validation ensures broad accessibility across operating systems but requires users to adopt consistent naming conventions (e.g., replacing spaces with underscores). Future solutions might abstract path complexities further, but awareness of current limits remains crucial for seamless cloud storage usage.