Every Flash ranked from weakest to strongest
3. The DCEU Flash
The DC Extended Universe may have missed its opportunity to produce a successful Flash movie, but it did manage to give us the Scarlet Speedster's first foray onto the silver screen in a headlining capacity. But by the time The Flash was actually released in movie theaters, we were already pretty familiar with Ezra Miller's Barry Allen, as he was one of the DCEU's recurring heroes and played a substantial role in Justice League.
"Substantial" means two different things depending on which version of Justice League you're talking about. He appeared for a significant amount of time in the reviled theatrical cut, but it was Zack Snyder's Justice League that actually made use of him, showcasing what he could do.
The Barry we meet in the DCEU is young and inexperienced, but he is capable of mastering his abilities on occasion; look no further than the epic moment where he ran back in time to save the Justice League from Darkseid's arrival. This Flash doesn't just run fast, he can run through time, altering events and creating whole new timelines and universes. That was, after all, the plot of the character's own movie.
The Flash is one of the most powerful members of the Justice League and the DCEU was only beginning to acknowledge that when it ended. That leaves this iteration of the character feeling like a case of "what could have been". Nevertheless, he had all the potential in the world to be the most powerful, but his inexperience and impulsiveness held him back a great deal.