The initial concept was to create a service similar to TechTV but "geared more toward MTV's demographics". The network was launched with thirteen original series. G4 was created and originally led by Charles Hirschhorn, a former president of Walt Disney Television and Television Animation. He expected video game creators themselves to eventually produce programming for the network. He envisioned that G4 could follow in the footsteps of MTV which in his opinion provided music video producers with a venue for non-traditional television programming. Hirschhorn intended G4 to become a vehicle for unconventional advertising. In 2002, G4 offered advertisers wide latitude to place their products on G4's programs, and even allowing their commercials to appear as if they're a part of the program.[6] G4 also offered what was called a "2 minute unit" which was an advertising package played as if it were part of a G4 program that was long enough to run an entire movie trailer. G4 also offered to sell the right to have a game showcased on the show Pulse.

As early as 2002, Comcast, the parent company of G4 dropped TechTV from its channel lineups, giving preference to its G4 network and reducing the value of TechTV in the hopes of a possible merger of the two networks. On March 25, 2004, Vulcan Inc. confirmed that they sold TechTV to G4 Media which merged both channels to become G4techTV. Days before the announced sale, Comcast made plans to close the original TechTV production facilities and workforce located in San Francisco, and offered new network headquarters in Los Angeles with openings for 80-100 of the TechTV employees available if they were willing to relocate. Hirschhorn headed the combined entity. Networks carrying both channels shut down the TechTV channel post-merger, while G4 enjoyed expansion onto systems carrying only TechTV and not G4 as a result of the merger. On February 15, 2005, less than a year after the merger, the letters, "TechTV", were officially dropped from the channel's name in the U.S. and the channel became known again as G4. However, on the network's affiliate in Canada, the "TechTV" letters remained a part of the name until mid-2009, when the channel was renamed G4 Canada. The only remaining TechTV originated show on G4 is X-Play, which also featured Adam Sessler, who was part of TechTV since its creation in 1998 as ZDTV. Adam Sessler left on April 25, 2012. His co-host, Morgan Webb, remains the only TechTV employee still at the network, with Kevin Pereira, the final pre-merger G4 host, leaving the channel after the network's E3 2012 coverage in early June 2012.

In September 2005, Neal Tiles replaced Hirschhorn as the channel's president. Tiles had previously been a senior marketing executive at DirecTV, Fox Sports and ESPN. He announced that G4 would be retooled as a male-oriented network, and that the channel would do away with the video game format. He stated that "Guys like to play games, but not necessarily watch a bunch of shows with games on the screen,' Tiles says. 'So what we're doing now is expanding G4 from a network solely defined by videogames to one inspired by them.'"

Comcast, the parent company of both G4 and E! television channels, announced on October 12, 2006, that it would consolidate its west coast entertainment operations, including G4, E! and Style into a new group headed by Ted Harbert, who had formerly run the E! channel. It was announced that the upper management of the G4 channel would relocate to the E! channel's Los Angeles office. On March 4, 2007, it was announced that the G4 Studios in Santa Monica, California, would close on April 15. Production of G4 programs was relocated to the Comcast Entertainment Group facility which housed E! and Style Network in the Wilshire Courtyard complex in the Miracle Mile neighborhood of Los Angeles (G4's original facility remains in use as an E! studio and office facility, mainly for that network's Chelsea Lately). As a consequence, many G4 employees involved in production were terminated. The sets of G4's original programs were also redesigned to fit within the new smaller spaces allocated to them.

Harbert gave his opinion at the time that the focus of the channel on "gaming has been demonstrated as being too narrow." He also gave assurances that while G4 might change, it would not become extinct. Design Studios Onesize and yU+Co teamed up to rebrand the G4 network as part of the transition. These changes to the network's programming would soon bring on a storm of criticism from TechTV/G4 fans, with many claiming that the channel has strayed too far from its gaming and technology roots, and have accused the channel of solely relying on shows like X-Play and Attack of the Show!. With most of the remaining G4 original shows having been severely altered, many saw this as G4's ongoing attempt to be a competitor to other male-oriented networks such as Spike.

On October 26, 2012 it was announced that X-Play and Attack of the Show! would cease by the end of 2012. This would end all of G4's studio programming, leaving it only airing acquired and syndicated programming. Reports of G4 rebranding itself in 2013 into an upscale men's channel appeared previous to the recent programming changes. In December 2012 NBCUniversal inked a brand licensing deal with Hearst Corporation, the owner of Esquire magazine, to turn G4 into The Esquire Network, which will air shows aimed at a metrosexual audience about travel, cooking, fashion and non-sports related male progamming. X-Play and Attack of the Show! aired their final original episodes (taped a month earlier) on January 23, 2013. The rebranding is scheduled to take place on April 22, 2013.