How to Resume Partial Downloads with aria2c on Ubuntu

This guide explains how to resume interrupted downloads using the aria2c command-line utility on Ubuntu. You will learn the specific commands required to continue fetching partially downloaded files without starting over, ensuring efficient bandwidth usage and faster completion times for large files.

Install aria2

Before beginning, ensure aria2 is installed on your system. Open your terminal and run the following command:

sudo apt update && sudo apt install aria2

Resume a Download

To resume a partially downloaded file, use the -c or --continue flag followed by the original URL. Run this command in the same directory where the incomplete file exists:

aria2c -c https://example.com/file.zip

If you have multiple URLs stored in a text file, you can resume all of them using:

aria2c -c -i urls.txt

How It Works

The -c flag tells aria2c to check for existing files in the current directory. If a partially downloaded file is found, it requests the remaining data from the server instead of downloading the entire file again. Note that the remote server must support range requests for this feature to function correctly.

Verify Completion

Once the command finishes, check the terminal output for a summary. It should indicate that the download status is complete. You can also verify the file size matches the expected size listed on the download source.