Latest Steam In-Game Overlay user agents:

User Agent Platform Device
Mozilla/5.0 (X11; Linux x86_64; Valve Steam GameOverlay/default/0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.6478.183 Safari/537.36 Dooble/2023.11.30 GNU/Linux Unknown
Mozilla/5.0 (X11; Linux x86_64; Valve Steam GameOverlay/default/0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.6478.183 Safari/537.36 GNU/Linux Unknown
Mozilla/5.0 (X11; Linux x86_64; Valve Steam GameOverlay/default/0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/109.0.5414.120 Safari/537.36 GNU/Linux Unknown
Mozilla/5.0 (X11; Linux x86_64; Valve Steam GameOverlay/0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/85.0.4183.121 Safari/537.36 GNU/Linux Unknown
Mozilla/5.0 (X11; Linux x86_64; Valve Steam GameOverlay/0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/109.0.5414.120 Safari/537.36 GNU/Linux Unknown
Mozilla/5.0 (Windows; U; Windows NT 6.3; en-US; Valve Steam GameOverlay/0; ) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/84.0.4147.105 Safari/537.36 Windows 8 Unknown
Mozilla/5.0 (Windows; U; Windows NT 6.2; en-US; Valve Steam GameOverlay/0; ) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/47.0.2526.49 Safari/537.36 Windows 8 Unknown
Mozilla/5.0 (Windows; U; Windows NT 6.2; en-US; Valve Steam GameOverlay/0; ) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/43.0.2357.81 Safari/537.36 Windows 8 Unknown
Mozilla/5.0 (Windows; U; Windows NT 10.0; en-US; Valve Steam GameOverlay/0; ) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/85.0.4183.121 Safari/537.36 Windows 10 Unknown
Mozilla/5.0 (Windows; U; Windows NT 10.0; en-US; Valve Steam GameOverlay/0; ) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/84.0.4147.105 Safari/537.36 Windows 10 Unknown