DevOps & APIs • Published August 17, 2026

cURL File Download & Upload: Handling Large Files, Resuming & Multipart Forms

Master file downloading and uploading with cURL. Learn -O, -o, resuming interrupted downloads (-C -), bandwidth throttling (--limit-rate), and multipart uploads.

Master file transfer operations with cURL. Learn how to download large archives, resume broken downloads with -C, limit bandwidth speed, and upload files via multipart/form-data or SFTP/FTP.

Frequently Asked Questions

Q1. How do I download multiple files simultaneously with cURL?

You can specify multiple URLs or URL globbing patterns: curl -O https://example.com/images/img[1-10].png or use the --parallel flag (supported in cURL 7.66.0+) for concurrent downloads.

Q2. How do I show a clean progress bar instead of the verbose transfer table?

Use the -# (or --progress-bar) flag: curl -# -O https://example.com/largefile.iso.

Q3. How do I download a file only if it has been modified on the server?

Use the -z flag with a timestamp or local file reference: curl -z local_backup.tar.gz -O https://example.com/backup.tar.gz.

Q4. How do I upload a file via SFTP or FTP using cURL?

Use the -T (or --upload-file) flag: curl -u "user:pass" -T backup.sql ftp://ftp.example.com/backups/.