Japan destroys internet speed record with new fiber optic technology

The National Institute of Information and Communications Technology (NICT) in Japan has set a groundbreaking record: a data transmission rate of 1.02 petabits per second (around 127,500 GB/s) over 1,802 kilometers (about 1,120 miles), reports CNET.

That’s around 350,000 times faster than the average US fixed broadband internet connection, which was around 289 Mbps according to Speedtest as of May 2025. At this new record-breaking speed, you could download the entire Netflix library in under a second.

Fiber optics with 19 cores

The key to the record is a new optical fiber with 19 cores, which are installed in a cable with a diameter of just 0.125 millimeters (the standard size for existing networks). Compared to conventional cables with one core, this fiber transmits 19 times more data with minimal data loss due to uniform light conduction. For transmission over the 1,120-mile distance—comparable to New York to Chicago—the signal was amplified 21 times.

The new record more than doubles the previous year’s figure of 50,250 GB/s. In 2023, the NICT team achieved similar speeds but only over a third of the distance. Advances in signal amplification and reduction of data loss are what made this new range possible.

Compatible with existing fiber optic cables

The technology could meet the growing demand for data worldwide, as data volumes have been increasing by about 50 percent annually according to Nielsen’s Law.

In general, the new technology is exciting and also interesting for countries where fiber optic expansion is stagnating, primarily because these new cables fit into existing infrastructures.

The record has not yet been independently verified, but it shows how fiber optics could further shape the future of the internet.