The maximum speed of the superhero known as the Flash varies depending on the comic book or adaptation in question, as different writers and storylines may portray the character with varying levels of power and speed. However, the Flash is consistently depicted as one of the fastest characters in the DC Comics universe.
The most well-known iteration of the Flash is Barry Allen, and his top speed is often stated to be the speed of light, which is approximately 299,792,458 meters per second in a vacuum. At this speed, he can travel through time and dimensions, phase through solid objects, and even create powerful shockwaves.
It's worth noting that the Flash's speed has been described differently in certain storylines or alternate versions of the character. For example, in some instances, the Flash has been shown to break the time barrier and exceed the speed of light. Additionally, other characters who have taken up the mantle of the Flash, such as Wally West or Jay Garrick, have also demonstrated extraordinary superhuman speed, although their top speeds may vary.
In summary, the Flash is typically portrayed as having the ability to reach or exceed the speed of light, making him one of the fastest superheroes in comic book lore.