- I gotta run.
Bart Allen was born to Don Allen, the son of Barry Allen, the second Flash, and his wife Meloni, the daughter of President Thawne of Earth and descendent of the evil Professor Zoom, in the late 30th century. Bart was born with his grandfather's speed. He had incredibly high metabolism and also aged at hyperspeed. When he was two years old, he physically looked twelve. The Thawne family had hated the Allen family for hundreds of years. President Thawne had the Dominators kill Don and his twin sister, Dawn. The Dominators kidnapped Bart, who was later captured by Earthgov for observation. The scientists of Earthgov raised him in a virtual reality environment so that he aged as swiftly mentally as he did physically. Bart was going to die of old age and Earthgov was not doing anything to fix his problem. His grandmother Iris took him away and brought him back to the 20th century, so that her nephew, Wally West, the third Flash, could show him how to control his speed. He adopted the identity Impulse.
After Wally helped him solve his problem and Bart helped him to defeat Kobra, Bart moved to Manchester, Alabama with Max Mercury. Wally had used his connections to supply Bart with a birth certificate, etc. Bart began the ninth grade at Manchester Junior High. He managed to make quite a few friends, chief among them Carol Bucklen. Max continued to train him in the art of superspeed, having him run obstacle courses while dodging axes and knives, solving jigsaw puzzles in mid-air, and the like. During this time, he became one of the founding members of Young Justice.
Kid FlashFollowing the breakup of Young Justice, Bart joined the new Teen Titans. He soon had his kneecap blown out by Deathstroke (who was at the time possessed by Jericho) and replaced with an artificial one. While recovering, Bart read every single book in the San Francisco Public Library and reinvented himself as the new Kid Flash. Even with the artificial kneecap, he could still run close to light speed.
After Superboy-Prime attacked Conner Kent (Superboy) in Smallville and injured or killed many Teen Titans, Bart joined with Wally West and Jay Garrick to stop the rampage of Superboy-Prime by running him at top speed into the Speed Force. Jay reached his limit before entering the Speed Force and Wally turned into energy and vanished, leaving Bart alone with Superboy-Prime. Barry Allen, Johnny Quick and Max Mercury, all of whom had previously been absorbed into the Speed Force, appeared and aided Bart. After taking Superboy-Prime into the Speed Force, Barry told Bart that "Wally is waiting for you". After they disappeared, Jay claimed that the Speed Force was gone.
A speedster wearing Barry's costume returned in Tokyo shortly thereafter to warn of the return of Superboy-Prime. This same Flash, still wearing Barry Allen's costume, would appear in the middle of the Battle of Metropolis against the army of escaped supervillains. Superboy-Prime reveals that the person in the Flash costume is Bart Allen, years older. Bart explains to the nearby Wonder Girl (who is suprised by her fellow Titan's transformation) that his grandfather's uniform was the only thing that could survive the trip back from where he had been, and that he was the only one there "who could still run". Bart then unleashed his anger against Superboy Prime for killing Conner Kent, pummeling him at superspeed and forcing Superboy to retreat from the battle. When the crisis is over, Bart explained to Jay that he spent years in an unknown dimension where he grew older. Bart confirmed that the Speed Force was destroyed and he used up the residual speed locked in his body fighting in Metropolis. He gave Barry's costume to Jay and says Jay was now the fastest man alive again.
Bart shunned his super-heroic past for the next year. He got a job working at Keystone Motors and began sharing an apartment with another young man named Griffin Grey. However, he was still connected to the Speed Force, but the connection threatened to kill him. S.T.A.R. Labs modified one of his grandfather's old costumes to help him control his connection. While at first he refused to don the costume, he finally gave in and became the fourth Flash. He also began a relationship with S.T.A.R. Labs employee Valerie Perez.
Bart decided to get a fresh start and moved to Los Angeles, applying for a job in forensics in their police department.
Inertia hired the Rogues to help him build a device in Los Angeles with the purpose of transferring the Speed Force from Bart to himself. Despite warnings from his grandmother, Bart confronted them. The machine was successful in removing his powers, but in doing so, it threatened to detonate with the energy of several atomic bombs. Bart sacrificed himself heroically, distracting the Rogues while Val deactivated the machine.
A funeral was held for Bart in a stadium in Keystone City. It was attended by a large number of costumed heroes and televised around the world. Eulogies were given by Jay Garrick, who revealed Bart's secret identity to the world, and Bart's former teammates Cyborg, Wonder Girl, and Robin. The funeral ended with the presentation of a video he had recorded shortly after becoming Kid Flash, to be shown in the event of his death.
Recently during Final Crisis: Legion of 3 Worlds, XS charged a lightning rod with the assistance of different versions of Garth and Ayla Ranzz in order to restore Bart to life. Bart returned as a teenager again and he received his Kid Flash costume ring from Brainiac 5.
Titans of Tomorrow
- In this storyline, Bart assumed the mantle of the Flash after the current Flash died in a "Crisis". In this alternate future, he was able to steal the speed of others, a power he used on his past self. At first, he appeared to be working with the Titans of Tomorrow, but was secretly spying on those Titans on the behalf of the resistance group formed by the Cyborg of this alternate future, Titans East. In this future, Bart had a romantic relationship with Rose Wilson, the Ravager.
Super Speed: Bart is a metahuman who can run and move his limbs at superhuman speeds. Biologically inherited ability to tap into the energy known as the Speed force. As Kid Flash, Bart was able to achieve speeds faster than Mach 10, but after he returned as an adult, Bart was fast enough to achieve speeds just short of light-speed and exceeding it when the need arised. Wally West the current Flash has stated that Bart was faster than all the Flashes combined. Bart has also said he is the fastest man to ever live; whether these statements are hyperbole or not is unknown. Bart can lend speed to or borrow speed from moving objects, create objects of concentrated Speed Force energy, become intangible by vibrating his molecular mass, perform both limited time and inter-dimensional travel and heal personal injuries by accelerating his metabolism. In recent years, with the knowledge and mastery of the Speed Force at his disposal, Bart has managed to reach seemingly impossible speeds, reaching as fast as the speed of thought. Bart is able to run across the surface of large bodies of water such as oceans. Bart can create wind vortexes by running in circles or rotating his arms and legs.
Speed Force Avatars: He has the ability to produce "scouts", Speed Force avatars he could send through the timestream, but has infrequently used it since the death of one put him in a coma.
Time Alteration Resistance: He has also proven resistant to alterations in the time stream, possibly due to an oddity of his origin; his parents met only in post-Zero Hour continuity, but he actually arrived before the event.
Photographic Memory: Most recently, it has been discovered that, unlike other speedsters, his photographic memory allows him to recall everything from his speed-reading. For several issues after this revelation, Bart was shown spouting encyclopedic information concerning the situation at hand.  This is inconsistent with known continuity as it had been previously established by Max Mercury that those with super-speed cannot permanently retain information if they acquired it through anything other than normal learning processes. 
Air Friction Reduction Aura: possesses an aura that prevents air friction from affecting his body and clothes while moving.
Speed Force Embodiment: Speed Force is a vaguely defined extradimensional energy force from which most superspeed-powered heroes draw their powers. The Speed Force serves as the ultimate measure of velocity in the DCU. They are often referred to in terms of barriers: Sound barrier, Light barrier, Time Barrier, Dimensional Barrier, and finally the Speed Force Barrier. Since Infinite Crisis, Bart's connection to the Speed Force has been more difficult to control. When he taps into the Speed Force, Bart appears to have electricity crackling around him, and has become so lethal, that he needs to wear the Flash suit while running in order to prevent it from killing him. However, he is no longer just a conduit he is now one with the Speed Force. This means that he and the Speed Force are one in the same. The result of this is that he could possibly be the most powerful flash in history.
- Metabolize Wounds: Accelerating his healing factor while using the Force to sustain him, he could heal from grievous injury, however it should be noted that his injuries may not "heal right" and medical care may still be required.
- Superhuman Stamina: Due to his connection with the Speed Field, Bart's stamina recuperates at an accelerated rate.
Molecular Control: ability to control the vibration of his molecules to the degree that he could vibrate through solid objects. West can cause whatever he vibrates through to explode .
Bio-Fission: Shortly before the Our Worlds at War event, Bart Allen developed the ability to create clone duplicates of himself. The clones always obeyed Bart's commands, and fused back with him once a task was completed. One of these clones was killed during a Young Justice mission to Apokolips, causing great physical trauma to Bart. After that event, Bart never used the power again.
Flashes and other super-speedsters also have the ability to speak to one another at a highly accelerated rate. He is capable of speed-reading at superhuman rates.
- Bart's first appearance as Kid Flash was Teen Titans (Volume 3) #4.
- His first appearance as the Flash was Flash: The Fastest Man Alive #2.
- Bart Allen appeared on the "Run" episode of the WB television series, Smallville. Actor Kyle Gallner played the part of Bart Allen.
- Bart has been quoted on several occasions stating that he would never become Kid Flash.
- Bart once shaved his head. Due to his accelerated metabolism, his hair grew back fairly quickly.
- Bart once had a Green Lantern tattoo on his left shoulder, as a means of helping to secure his secret identity as Kid Flash. However, due to his accelerated healing, his skin perceived the tattoo ink as a poison and quickly purged it from his system.
- Bart was originally slated to become a member of the Justice League for the Justice League animated series, but his inclusion was dropped from consideration during pre-production. Early dailies for Justice League included in the Justice League Volume 1 DVD set show a teaser preview with Impulse on the team.
- Batman is often credited with providing Bart the nickname Impulse. This is erroneous as it was Bart who gave himself the name after Wally West accused him of being too "impulsive."
- 565 Appearances of Bart Allen (New Earth)
- 233 Images featuring Bart Allen (New Earth)
- 104 Quotations by or about Bart Allen (New Earth)
- Character Gallery: Bart Allen (New Earth)
Flash (Wally West), Flash (Jay Garrick)
Flash (Wally West), Flash (Jay Garrick)