Hoptroff is a provider of distributed timing services, based in London, England.

The company was previously a watch manufacturer based in London, England, known for its atomic clock and high accuracy watches.^{[1][2][3][4][5]}

Hoptroff was founded in 2010 as Hoptroff London by Richard Hoptroff,^[6] a physicist with the original intention of supplying smart mechanical watch movements to the industry.^[7] In 2012, the company incorporated Bluetooth Low Energy technology^[4] to its watches for the movement and sync with the mobile phones for configuration in order to display internet connected information.^[6][8]

In April 2013, the company unveiled its first atomic timepiece in London, which conceptualized it as a new variety of time regulation devices in clocks and watches, that could be placed alongside the balance spring, quartz crystal and the pendulum.^[5] After the launch, the brand gained a reputation for the most accurate watch ever produced^[9] and was mentioned in several media outlets, such as New York Times, Engadget, The Telegraph and others.^[10] In 2015, Hoptroff London launched a classic quartz watch range with a claim to being the first watchmaker to achieve better than one second per year accuracy in its quartz watches.^[11][12]

In 2015, the company repositioned itself as Hoptroff London Limited and started work building a proprietary network of timing hubs, incorporating Grand Master atomic clocks, in London, New York and Tokyo.

In 2020, Hoptroff successfully raised £982,700 through crowd funding, with the goal towards developing a global distributed timing network.^[13]

Hoptroff London watches are advertised by the company as "The most accurate timepieces in the world”. Its atomic timepieces use chip scale atomic clock technology,^[14] where a small vessel of Caesium 133 is exposed to 130 °C.^[15] A laser is used to excite the atoms and a microwave resonator which causes the hyperfine transition frequency of the atoms. The resultant watch after this process has a higher accuracy of 1.5 seconds every thousand years.^[16][17]

However, the technology used its quartz timepieces is still unknown to the public.^[15]

As of 2015, the company moved away from watch production to focus on high accuracy time synchronization software for companies operating across distributed infrastructure.

• Bluetooth low energy
• Chip-scale atomic clock