Boost Linux Downloads with Axel: Faster FTP/HTTP Transfers Explained

What is Axel?

Axel is a lightweight, dependency‑free (aside from gcc and make) command‑line download accelerator for Linux that clones wget’s functionality while using multiple simultaneous connections to speed up HTTP and FTP transfers.

Installation

Axel can be installed from the default repositories of most major Linux distributions:

CentOS/RHEL 7/8: enable EPEL then yum install epel-release && yum install axel Fedora: dnf install axel (or yum install axel on older versions)

Debian/Ubuntu/Linux Mint: sudo aptitude install axel Arch/Manjaro: sudo pacman -S axel OpenSUSE:

sudo zypper install axel

Configuration Options

Axel reads settings from /etc/axelrc (or a user‑specific file). The most useful options include:

reconnect_delay : seconds to wait before re‑trying a failed connection.

max_speed : maximum download rate in bytes per second (B/s). Setting this prevents Axel from saturating the network.

num_connections : maximum number of parallel connections (default 4, often sufficient).

connection_timeout : seconds to wait for a response before aborting and retrying.

http_proxy / https_proxy : proxy server in the form http://host:port.

no_proxy : comma‑separated list of hostnames/IPs that should bypass the proxy.

buffer_size : maximum bytes read from all connections in a single read operation.

verbose : set to 1 to display progress messages, 0 to silence them.

interface : specify which network interface to use when multiple are present.

All command‑line options correspond to these configuration entries; command‑line flags override the file values.

Performance Test Setup

To compare Axel with wget, a 100 MiB test file was downloaded via both FTP and HTTP from ftp://speedtest:[email protected]/test100Mb.db and http://speedtest.ftp.otenet.gr/files/test100Mb.db. Axel was invoked with ten parallel connections and an explicit output filename.

FTP Download Comparison

Using wget:

wget ftp://speedtest:[email protected]/test100Mb.db

Result: average 205 KB/s, total time 8 min 7 s.

Using Axel:

axel -n 10 --output=axel-test100Mb.db ftp://speedtest:[email protected]/test100Mb.db

Result: average 2 734 KB/s, total time 37 s.

HTTP Download Comparison

Using wget:

wget http://speedtest.ftp.otenet.gr/files/test100Mb.db

Result: average 226 KB/s.

Using Axel:

axel -n 10 --output=axel-test100Mb.db http://speedtest.ftp.otenet.gr/files/test100Mb.db

Result: average 2 458 KB/s.

Conclusion

The tests show that Axel can dramatically increase download speeds for both FTP and HTTP by opening multiple simultaneous connections and consolidating the data into a single output file. By tuning configuration options such as num_connections and max_speed, users can adapt Axel to their network conditions and achieve faster, more efficient transfers.