Joshua Charlie Joseph Bradley (born 4 September 1992), better known by his online alias Zerkaa, is an English YouTuber, Twitch streamer, influencer, and Internet personality. He is a member of the British YouTube group, the Sidemen. In 2019, he was listed as the ninth most influential online creator in the United Kingdom by The Sunday Times. In 2022, he was the most watched Twitch streamer in the United Kingdom, with 17.68 million hours watched.
Joshua Bradley was born on 4 September 1992 in Bermondsey, London. He attended Bexley Grammar School in Welling, where he met future fellow Sidemen member Tobi Brown. He claims to have had an interest in architecture in his early years, and used to love designing houses. As a child, Bradley took dance lessons and competed in street dance performances. His parents went through a divorce growing up, which he states led to him playing games. He claims to have played Call of Duty in his room for 8 hours, because he wanted an escape from the stress of his parents' divorce. In the Netflix documentary, The Sidemen Story, Bradley had mentioned that he suffered from anxiety.
He later attended Ravensbourne University and earned an upper second honours degree in digital film production. Before getting into content creation, Bradley tried working in a bank in London with his father, who was a banker himself, but left soon after. He also had a week-long stint at the Sky Sports studio.
In 2009, Bradley created his first YouTube channel, Zerkaa, to which he primarily uploaded video game content from games like Call of Duty and FIFA. He has subsequently launched six more solo YouTube channels — namely ZerkaaPlays, ZerkaaReacts, ZerkaaLive, ZerkaaActuallyPlays, ZerkaaGuesses, and ZerkaaCards.
In October 2013, Bradley co-founded and became a member of the British YouTuber group, the Sidemen. He is the eldest amongst the seven members of the Sidemen. He lived with three other members of the group — Vikkstar, KSI, and Miniminter — from 2014 until 2018, creating content regularly, after which he moved into an apartment with his girlfriend. The Sidemen publishes content around a variety of themes including challenges, sketches and video game commentaries.
In 2018, Bradley co-starred alongside the rest of the Sidemen in the YouTube Premium series The Sidemen Show. In 2019, Bradley was listed as the ninth most influential online creator in the United Kingdom by The Sunday Times. In a 2021 article discussing gambling issues surrounding the FIFA game series, Bradley was cited by The Sunday Times as an example of a YouTuber sponsored by EA to make pack-opening videos.
Bradley started streaming on Twitch in 2010. He is also a Twitch partner. In 2022, he was the most watched Twitch streamer in the United Kingdom, with 17.68 million hours watched. He was also cited as a streamer featuring walkthroughs of the 2023 video game Hogwarts Legacy by Guinness World Records. He was nominated for Best Role-play Streamer at the 2022 Streamer Awards.
Bradley and the Sidemen have founded multiple businesses throughout their online careers. In 2014, the group launched a clothing brand under the Sidemen Clothing banner. In November 2021, they founded a restaurant chain Sides in collaboration with Reef. In October 2022, they launched their own vodka brand, XIX Vodka. In March 2024, they launched a breakfast cereal brand, Best Cereal, in collaboration with Mornflake. In May 2025, they launched their own venture capital firm, Upside VC. Bradley was a Director of the firm but has formally resigned from the position.
In 2017, Bradley launched his own clothing line, ZRK London, selling streetwear apparels like T-shirts, hoodies, and caps. In 2023, the clothing line was renamed to Internet Made.
Bradley has been in a relationship with Freya Nightingale since 2010. They were engaged on 15 January 2024, and got married on 6 September 2025 in France. On 7 June 2026, Bradley announced via Instagram that they were expecting their first child.
Bradley is a supporter of Millwall F.C. and claims to have a season ticket since he was six years old.