How to Increase Concurrent Downloads in aria2?

The lightweight, multi-protocol command-line download utility aria2 is renowned for its speed and efficiency, but its default settings often limit its full potential. By default, aria2 restricts the number of simultaneous downloads and connections per server to prevent overwhelming remote hosts. However, if you have a high-bandwidth internet connection and need to download multiple files quickly, you can easily modify these limits. This article provides a straightforward guide on how to increase your concurrent downloads in aria2 using command-line flags or a permanent configuration file.

Adjusting Downloads via Command-Line Flags

If you only need to boost your download limits for a single session, the quickest method is to pass specific arguments directly into your terminal command. The key parameter for concurrent downloads is --max-concurrent-downloads.

To increase your simultaneous file downloads, use the following structure:

aria2c --max-concurrent-downloads=10 https://example.com/file1.zip https://example.com/file2.zip

To truly maximize your download speeds, you should also consider increasing the number of connections allowed per server and the number of split pieces per file. You can combine these flags like this:

aria2c --max-concurrent-downloads=10 --max-connection-per-server=16 --split=16 https://example.com/file.zip

• –max-concurrent-downloads: Sets the maximum number of parallel file downloads (default is 5).
• –max-connection-per-server: Specifies the maximum number of connections to a single server per download (default is 1, max is 16).
• –split: Defines the number of segments to split a single file into for parallel downloading.

Making the Changes Permanent via Configuration File

Specifying flags every time you run a command can become tedious. To apply these speed and download optimizations permanently, you can add them to the aria2 configuration file (aria2.conf).

Depending on your operating system, the configuration file is typically located in one of these directories:

• Linux/macOS: ~/.config/aria2/aria2.conf or ~/.aria2/aria2.conf
• Windows: The same directory where your aria2c.exe is located, or a custom path specified at startup.

Open your aria2.conf file in a text editor and add or modify the following lines:

# Maximum number of concurrent downloads
max-concurrent-downloads=10

# Maximum number of connections to one server per download
max-connection-per-server=16

# Minimum split size; allocated if file size is larger than this value
min-split-size=20M

# Number of splits per file
split=16

# Continue downloading a partially downloaded file
continue=true

Once you save the file, aria2 will automatically apply these optimized limits every time you launch the application without requiring extra command-line flags.