The original WRT54G was first released in December 2002. It comes with a 4+1 port network switch (the Internet/WAN port is also in the same internal network switch, but on a different VLAN). The devices have two removable antennas connected through Reverse Polarity TNC connectors. The WRT54GC router is an exception and has an internal antenna with optional external antenna. As a cost-cutting measure, the design of the latest version of the WRT54G no longer has detachable antennas or TNC connectors. Instead, version 8 routers simply route thin wires into antenna 'shells' eliminating the connector. As a result, Linksys HGA7T and similar external antennas are no longer compatible with this model.

Linksys WRT54GS version 1.1

Linksys WRT54GL version 1.1

WRT54G version 2.0 with upgraded antennas

Linksys WRT54G-TM

Linksys WRTU54G-TM

Linksys WRT54GX version 2

The WRT54GS is nearly identical to WRT54G except for additional RAM, flash memory, and SpeedBooster software. Versions 1 to 3 of this router have 8MB of flash memory. Since most third parties' firmware only use up to 4MB flash, a JFFS2-based read/write filesystem can be created and used on the remaining 4MB free flash. This allows for greater flexibility of configurations and scripting, enabling this small router to both load balance multiple ADSL lines (multi homed) or to be run as a hardware layer 2 load balancer (with appropriate third party firmware).

Linksys released the WRT54GL in 2005 to support third-party firmware based on Linux, after the original WRT54G line was switched from Linux to VxWorks, starting with version 5. The WRT54GL is technically a reissue of the version 4 WRT54G. Cisco was sued by the FSF for copyright infringement, but the case was settled.

WRTSL54GS is similar to the WRT54GS while adding additional firmware features and a USB 2.0 port (referred to as StorageLink) which can be used for a USB hard disk or flash drive.