What Is the Bitcoin Mempool?
The Bitcoin mempool (memory pool) is a holding area for unconfirmed transactions waiting to be included in the next block. When network demand is high, the mempool fills up and fee rates rise — miners prioritize transactions with higher fees per virtual byte (sat/vB). The BTC.PH Mempool Visualizer pulls live data from mempool.space every 15 seconds and displays fee tiers as color-coded bars so you can instantly see which fee level to use for your desired confirmation speed.
The five fee tiers range from minimum (no priority, may take days) to fastest (next block, ~10 minutes). During times of low congestion, the difference between economy and urgent fees is often minimal. During peak demand (like after a major market move), urgent fees can spike 10x or more. Use the "Best time to send" indicator as a quick guide. For more BTC network stats including the current block height and hash rate, visit the Dashboard, or check the Halving Countdown for block progress.