The video, posted by Daniel Van Duren, was taped from less than 1km away from the twin blasts that rocked the port town at 11:30 p.m. Wednesday, according to a description on the page.
According to Van Duren's YouTube page, he was on top of his 33-story apartment building when the blasts began.
"It was like watching a nuclear bomb go off in front of us!!" the post on the page says.
In the video onlookers can be heard exclaiming at the series of blasts, which send debris shooting out like fireworks.
Van Duren wrote that the blasts devastated his building along with many others.
"So we had to run down the whole 33 levels and escape," he wrote.
The explosions, which left at least 50 dead, including 12 firefighters, according to the Tianjin government, also injured more than 700.
There were scenes of devastation around Tianjin, including a field of cars that were burned out and windows blown out in the area.
Tianjin, China's fifth largest city, is the maritime gateway to Beijing.