A slow or crashing cPanel File Manager is a direct symptom of an overloaded shared server. When File Manager hangs while uploading files, times out when opening directories, or crashes the browser, the hosting server simply doesn't have the resources to serve you properly. This degrades every aspect of your website's performance.
For bulk uploads and large files, FTP (or better, SFTP) is more reliable than cPanel File Manager. Use FileZilla with SFTP settings: host=your-server-ip, port=22, protocol=SFTP.
File Manager runs on your hosting server. When the server is heavily loaded with other accounts' traffic and processes, File Manager gets slow along with everything else. You're experiencing the fundamental limitation of shared hosting.
Bagful VPS gives you dedicated I/O, CPU, and RAM. File Manager operations that take 30 seconds on shared hosting complete in 2-3 seconds on VPS. SFTP access is also available for large file transfers.
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