Bitcoin’s mining difficulty has fallen below its year-earlier level for only the second time in the network’s history as weak mining economics and the shift toward artificial intelligence weigh on capacity growth.
The metric, which measures how difficult it is to mine a Bitcoin block, is now at 126.23 trillion after falling 0.74%, about 1.1% below the 127.62 trillion reached a year earlier and 19.1% from the 155.97 trillion all-time high seen in November 2025.
Difficulty adjusts every 2,016 blocks, or roughly every two weeks, to keep Bitcoin’s average block time near 10 minutes. Falling difficulty indicates that less computing power was competing during the previous adjustment period, while reducing competition for miners that remain online.
The metric has dropped about 14% from its January peak, reached this year, following declines of 10% in June and 5% earlier in July, according to network data.
The only previous year-over-year decline was after China’s 2021 mining ban, which temporarily removed roughly half of the network’s computing power. Difficulty recovered as miners relocated to other regions.
This time around, the plunge is more mining economics-based.