In the future, tech giant Bubble unveils their latest creation: the B-bot, created by benevolent CEO Marc Weidell, with the intent to make a robotic buddy that is designed to help make friends and connect to the internet, using Marc's friendship algorithm installed in every B-Bot. In the town of Nonsuch, Barney Pudowski is the only middle schooler who does not own a B-bot. His former childhood friends, Savannah Meades, Rich Belcher, Noah and Ava have all become absorbed by their individual B-bots. Barney's father Graham, who sells novelties online, and his grandmother Donka come to realize that he does not have any friends and empathize when Rich plays a cruel prank on Barney. They hastily go to a Bubble store, but it's closed. Fortunately, a delivery driver had been holding onto a slightly damaged B-bot that had fallen out of his truck and sells it to them.

Barney gets the B-bot as a late birthday present, but upon activating it, quickly learns that it's defective and glitchy. Not wanting to upset his father, he decides to take it back to the Bubble store to get fixed. He ends up running into Rich and his friends who taunt and try to humiliate him. The B-bot begins to fight back, as his safety functions have been turned off, and he and Barney laugh together and run. However, Rich called the police and they along with Graham and Donka are taken to the Bubble store so that the B-bot can be crushed. Not wanting to see him go, Barney secretly rescues him and names him Ron, a shortened version of his model number.

When Barney and Ron's actions are reported, Marc is happy to see Ron go against his programming, while his COO Andrew Morris views it as bad publicity, believing Ron must been destroyed for the issue to be resolved. Barney teaches Ron how to be a good friend and, while hanging out, runs into Savannah who tells Ron that he needs to help Barney get friends. Despite Barney telling Savannah not to, she posts Ron's actions online, alerting Bubble. The next day, Ron gets out of the house and tries to get "friends" for Barney, bringing a series of random people to school. As Barney gets in trouble, Rich discovers Ron's unlocked function and downloads it, causing all the other B-bots to have their safety features and parental controls turned off. The B-bots run wild and, in the end, after the B-Bots have a patch update, Savannah is publicly humiliated.

Barney is suspended from school and tells Ron off, but upon returning home, realizes that Ron was truly being a friend and decides to run away with him when Bubble employees come for him. They briefly run into Savannah, still upset over her incident, and tells her that he is hiding in the woods. Meanwhile, while Andrew warns Marc about the ramifications of the B-bot, Marc sneaks away so that he can meet Ron while Bubble uses their resources to take control of all the B-bots to go looking for Ron and Barney after the duo are initially elated in the woods, but wind up getting lost and spending a scary, uncomfortable night there. But due to the cold weather and Barney's asthma, he becomes weak and Ron brings him back to civilization just outside the school where Savannah, Rich, Noah and Ava rush out to help him.

Barney is taken to the hospital and recuperates, before meeting Marc who is impressed with Ron. Marc fixes Ron's glitches and thereby makes him a different B-bot. Barney demands that Marc access the cloud to get Ron's original personality, but Andrew took over the company and locked Marc out. Through an elaborate plan for Barney, Graham, Donka, and Marc breaking into Bubble HQ, Barney manages to make it to the Bubble database, finds Ron's original data by his light, and uploads him back into his body, restoring him back to his original code. Seeing that Bubble has direct access to everyone's B-bot, and realizing that everyone is just as lonely as he was, Barney suggests upgrading all the B-bots to have Ron's flaws. However, this means that Ron will be dispersed into the internet. Barney reluctantly says goodbye to Ron as his programming is spread to everyone, mixing Marc's friendship algorithm with Ron's coding. Marc blackmails Andrew into giving his position of CEO back after secretly recording him admitting that the B-bots spy on their owners for profit.

Three months later, everyone has a faulty B-bot, but are happy with their wild and weird personalities. Barney no longer has one, but has become much more sociable and has gotten close with his former friends. As they hang out at the "Barney Bench" at recess, a giant Bubble tower that overlooks Nonsuch produces Ron's face, implying that he is still alive.