The CW’s The Flash became a stable fixture of the Arrowverse over its nine-season run, putting the eponymous Barry Allen, a.k.a. the Flash, front-and-center as the Fastest Man Alive. Grant Gustin originally debuted as Barry Allen in 2013 during Arrow season 2, The CW’s premiere series in the Arrowverse, before headlining his own show, The Flash, from 2014 to 2023. DC’s Flash has been adapted into live-action several times, including by Rod Haase in 1979, John Wesley Shipp in the 1990s, and Ezra Miller for the DCEU, but Grant Gustin’s portrayal of the Scarlet Speedster is the longest-running and most developed.
As a metahuman who gains superhuman speed after the explosion of STAR Labs’ particle accelerator, Barry Allen has a remarkable amount of power that is demonstrated throughout The Flash’s nine seasons. Barry’s powers have fluctuated over the years, but his ability to tap into the “Speed Force” not only allows him to boost his speed but also travel through time and even jump to alternate realities. Thanks to his remarkable gifts and brilliant mind, he quickly became the staunch protector of Central City, surrounding himself with loyal allies who help him defeat deadly threats and hone his talents to become the best superhero he can be.
Season One
After a brief introduction in Arrow season 2, episode 8, “The Scientist,” Gustin brought Barry Allen to life in The Flash season 1, which premiered on The CW in 2014. Waking up from a coma at STAR Labs, Barry found he could move at superhuman speeds, quickly setting a baseline for his powers by battling Clyde Mardon, a metahuman with the ability to control the weather. Running at a speed of over 700mph, just under the speed of sound, Barry was able to stop a tornado from forming and later broke the sound barrier when developing a supersonic punch that could defeat Tony Woodward, a man made of organic steel.
Being able to run faster than the speed of sound (clocking in at around 837mph to defeat Woodward), Barry taught himself to modulate his movements which allowed him to run those speeds without generating a sonic boom. By the end of The Flash season 1, Barry had learned how to use the Speed Force and phase through solid matter. His most impressive skill was showcased in The Flash’s season 1 finale, “Fast Enough,” which saw Barry run fast enough to travel through time, hoping to prevent his mother’s death at the hands of the Reverse Flash. He resisted this urge, however, but still clocked in at over 1500mph.
Season Two
The Flash season 2, which premiered on The CW in October 2015, saw Barry Allen diversifying his powers beyond superhuman speed. Under the tutelage of Jay Garrick (later revealed to be the speeding serial killer Zoom in disguise), Barry began mastering tricks such as throwing lightning and traveling between alternate realities of the Arrowverse. This season also saw Barry learn how to create a time remnant: a clone of himself borne of a potential future, created by the Speed Force to maintain the continuity of the timeline. Alongside these remarkable new talents, Barry’s speed continued to improve during The Flash season 2.
As well as developing the natural superhuman speed of a variety of speedsters in the Arrowverse, The Flash season 2 also introduced the dangerous drug Velocity 9, which could allow a temporary connection to the Speed Force. In order to battle a speedster enhanced with Velocity 9, Eliza Harmon, a.k.a. Trajectory, Barry had to run at roughly 2532mph. Throughout the season, Barry increased his base speed by training with a tachyon device, which eventually allowed him to travel between dimensions unaided, leading to his initial encounter with Kara Zor-El, a.k.a. Supergirl, on Earth-38. Though Barry briefly loses his abilities in The Flash season 2, he eventually achieves speeds over 10,000mph.
Season Three
The ending of The Flash season 2 sees Barry travel through time and save his mother’s life, which leads to season 3’s adaptation of DC Comics’ Flashpoint storyline. This timeline featured the emergence of Savitar, a god-like speedster with an immense grudge against Barry, who later turns out to be a clone of a future version of Barry himself. Savitar was so fast that Barry couldn’t detect him even with his connection to the Speed Force, making him a formidable villain who is eventually defeated as the Flash phased into his armor and exposed the new speedster, allowing him to be taken down by Barry’s love-interest Iris West.
The Flash season 3 also saw Wally West gain speedster powers from the mysterious Alchemy – a Savitar-possessed scientist – and the new speedster begins fighting alongside Barry Allen as Kid Flash. The pair test each other throughout the season, with Barry training the new hero so that he’s strong enough to save Iris after receiving visions of her future death. Barry also meets a speedster from another reality, Earth-2, named Jesse Quick, whom he tests himself against, being able to keep up with a comfortable jog at around 2300mph. At the end of the season, Barry imprisons himself inside the Speed Force as punishment for creating the Flashpoint timeline.
Season Four
Barry returned after six months in the Speed Force with a new level of speed and a number of new tricks. Perhaps the most impressive of these was “Flashtime”, a heightened sense of awareness that allowed Barry to boost his brain’s activity to react quickly to events around him, effectively stopping time to simulate near-perfect reflexes. Barry couldn’t use Flashtime for long before burning out, but he was able to train himself and his allies, Cisco Ramon and Caitlin Snow, to operate in a state of Flashtime for an elongated length of time. While no numerical speed was given for Flashtime, this must have been almost the speed of light.
An even more remarkable feat came during The Flash season 4, episode 12, “Honey, I Shrunk Team Flash,” which saw Barry’s life saved by a prison inmate known as Dave “Big Sir” Ratchet, a man who Barry learns is innocent of the crime he’s incarcerated for. In an effort to repay his debt, Barry helps Ratchet escape from prison, using his superhuman speed to break him free, relocating him to Jiaju, China. Assuming Barry and Ratchet traveled almost 7500 miles in a matter of seconds, Barry was running at around 120 million mph, a drop in the bucket compared to speeds demonstrated by Barry in earlier seasons of The Flash.
Season Five
The Flash season 5 didn’t do much to expand on Barry’s power level in the Arrowverse, as the majority of the season focused on the introduction of Nora West-Allen, the mysterious future daughter of Barry Allen and Iris West, who also happens to be a speedster. Her appearance in The Flash’s present-day timeline alter events, and eventually wipe this version of her from existence. Her timeline alterations also bring forward the terrifying “Crisis” event that was originally supposed to take place in 2024 but would then emerge in 2019 as the Arrowverse’s “Crisis on Infinite Earths” crossover event.
While not much emphasis was placed on Barry’s own powers during The Flash season 5, the Flash did express a greater understanding of his connection to the Speed Force and learned how to use it more passively than other speedsters – especially when training his own daughter. Barry was even able to drag Nora back to her own time with ease after learning that she had been working with the villainous Eobard Thawne, and warned her not to return as he would sense her in the Speed Force. The Flash season 5 acted as more of a character study for Barry Allen, Iris West, and Nora West-Allen.
Season Six
The first two episodes of The Flash season 6 offered definitive yet contradictory limits for the Flash’s speed. The season 6 premiere, “Into the Vortex,” saw Barry trying to save the stranded consciousness of Chester P. Runk by diving into a black hole, resulting in one of the most awe-inspiring visuals in The Flash‘s history. The Speed Force supposedly had a hand in protecting Barry from the immense gravity and lack of atmosphere in the black hole, but Barry had to have been running much faster than the speed of light to accomplish this impressive feat – somewhere over 670 million mph – proving his improvements over the series.
This was contradicted in the next episode, however, as Esperanza Garcia’s, a.k.a. Ultraviolet’s, light-emitting powers were said to be 80-times-faster than the Flash’s top speed, so Barry couldn’t have been traveling at the speed of light. This would make Barry’s top speed in The Flash at around 8.3 million mph, though it’s possible this is how fast Barry is without tapping into the Speed Force. During The Flash season 6, the transformative “Crisis on Infinite Earths” event occurs over all the Arrowverse’s series’, and the season also ends with the Speed Force dying, rendering all speedsters with no abilities whatsoever.
Season Seven
The Flash season 7 put a lot more emphasis on Barry Allen’s heart rather than his speed, so it didn’t do much to showcase how fast or powerful he has become over the course of the series. However, season 7 sees Barry and Iris West create an artificial Speed Force to replace the Speed Force that died at the end of season 6, allowing Barry to still harness his superhuman speed. While battling the manifestation of the Speed Force driven mad, Barry became capable of “speed-thinking,” being able to run calculations in his head faster than a quantum computer, though this newfound efficiency came at the cost of his humanity.
The reborn Speed Force claimed that Barry Allen was faster than ever before, but no actual numbers were given to quantify this level of speed. However, Barry’s powers were proven to have increased in The Flash’s season 7 finale, “Heart of the Matter, Part 2,” which featured the Flash facing a rejuvenated version of his greatest foe: the Reverse Flash. During this fight, Barry was able to avoid swings from the villain, catch a punch mid-air, and hurl his enemy several dozen feet. While Barry Allen has often incorrectly been called the Fastest Man Alive, this battle proved that he was actually worthy of that title.
Season Eight
The Flash season 8 picked up six months after season 7’s finale, kicking off with the Arrowverse’s “Armageddon” crossover event. This season was quick to establish that Barry’s powers had improved, with the opening scene featuring Caitlin Snow questioning why Barry would walk to get coffee when he “can run 4000 miles an hour.” Barry later went on to give a practical demonstration of his speed, evacuating two bullet trains before they collided, easily emptying both trains and covering a huge amount of distance in twelve seconds. Later on, Barry clocked in at around 15,000mph without the assistance of the Speed Force.
Season 8 pitted Barry Allen against some of his most formidable villains yet, including the re-emergence of Eobard Thawne, the psychic alien Despero, a malevolent entity known as Deathstorm, and the rise of the Negative Speed Force and the Negative Forces. During an epic battle in The Flash’s season 8 finale, “Negative, Part 2,” Thawne is chosen as the Negative Speed Force’s avatar and goes up against the Flash. Barry is able to reverse Thawne’s own attack, thrusting him out of the timeline and effectively resetting the Reverse Flash’s timeline, Reverse-Flashpoint, in which he was the Flash and Barry was the Reverse Flash.
Season Nine
Confirmed to be The Flash’s final season, season 9 opened by pitting Barry Allen against a new speedster known as Red Death, who turns out to be a version of Batwoman Ryan Wilder from Earth-4125. Barry Allen eventually manages to defeat Red Death with the main reality’s version of Batwoman though faces a new threat in the next part of the season, particularly in season 9, episode 9, “It’s My Party and I’ll Die If I Want To.” This episode marked Ramsey Rosso’s return at Barry Allen’s birthday party, a villain who turns Barry’s friends into zombies and manipulates Wally West into killing Barry and taking over the multiverse.
Barry Allen is resurrected by Oliver Queen, a.k.a. the Arrowverse’s Green Arrow, in the afterlife, with the latter briefly returning with the Scarlet Speedster to defeat Rosso and save his friends. Even so, this battle opens a gateway through the multiverse which could cause serious problems in the upcoming part of The Flash season 9. Over the years, Barry Allen has surrounded himself with allies, some of which have incredible powers of their own, so less focus has been given to his own abilities. Even so, with The Flash coming to an end in May 2023, there’s still time for Barry Allen to show off more of his remarkable powers.
