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The mempool is the waiting room for Bitcoin transactions: they have been broadcast, but no block includes them yet, and miners pick the highest-paying ones first. The Bitcoin Mempool page follows it live — which blocks were just mined and which are coming next, what it costs to get a transaction confirmed, and how crowded the queue is right now. Open it with Open mempool under the Latest Blocks widget in the Transactions section of the BTC ticker page, or go straight to i88.io/bitcoin/mempool; the breadcrumbs above the title lead back to Home and to the BTC ticker page. The page is laid out in four parts: the block strip across the top, then Fees and Network Congestion on the left and Unconfirmed transactions on the right. On a narrower screen the two columns stack into one.

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The block strip

A strip of block cards runs across the top of the page. Blocks already mined sit on the left, the oldest first, and blocks projected from the current mempool continue on the right, so the latest mined block and the next projected one meet in the middle. Flip blocks swaps the two sides. Drag the strip sideways with the mouse, or use the scrollbar under it, to see more blocks. Each card shows:
  • When. How long ago the block was mined, such as just now or 12 minutes ago. A projected block shows when it is expected instead, such as in ~10 min: it is not mined yet, so its contents and timing can still change.
  • Height and pool. The block number and the logo of the mining pool that found it; hover the logo for the pool’s name and website. Projected blocks have neither.
  • Size and transactions. How large the block is, in MB, and how many transactions it holds.
  • Fees. The median fee rate — half of the block’s transactions paid more, half paid less — and the range from the lowest to the highest fee rate in the block, in sat/vB.
The strip refreshes every 30 seconds.

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Fees

  • Transaction fees — the fee rates that get a transaction confirmed right now, from the slowest to the fastest. Each tier shows the rate in sat/vB, the estimated time to confirm, such as ~10 min or ~24 hours, and roughly what a typical transaction costs in US dollars.
  • Bitcoin Avg Transaction Fees (30d) — what an average transaction has cost over the past 30 days, as a chart, with the current figure beside it.
  • Bitcoin recommended fee calculator — choose how many blocks you are willing to wait, such as 1 block (~10 min), and the calculator shows the recommended fee rate in sat/vB and what it comes to in US dollars. A shorter target needs a higher fee; waiting longer usually lowers it.

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Network Congestion

  • Average block time — the average gap between blocks over the current difficulty epoch, such as ~9.5 minutes. The protocol targets 10 minutes; hover the label to see how many blocks the average covers so far.
  • Unconfirmed Transactions — how many transactions are sitting in the mempool, waiting for a block.
  • Network Status — Memory Usage shows how full the mempool is against its size limit, such as 3 / 300 MB, with a bar. When it fills up, the lowest-fee transactions are dropped and minimum fees rise.
  • Transaction Inflow — a chart of Incoming Transaction Volume over the last two hours, in virtual bytes per second (vB/s), set against a dashed Network Capacity line: how much transaction data the network can confirm on average. The inflow line is green while it stays below capacity, turns orange once it reaches capacity and red at twice capacity or more, and a badge at the right edge shows its latest value. When incoming volume stays above the capacity line, the mempool grows and fees go up.
Congestion figures refresh every 30 seconds and the inflow chart every minute.

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Unconfirmed transactions

Mempool Explorer lists the transactions still waiting, grouped by fee rate. Each row is a band of fee rates in sat/vB, a bar with the number of Transactions in that band, and how long they are expected to take to confirm. Where a band has a link, the arrow next to the time opens its transactions on an external site in a new tab.
Before you send bitcoin, read the page from right to left: Mempool Explorer shows where the queue is crowded, Network Congestion whether it is growing, and the calculator what fee gets you into the block you want.

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Asking about the mempool

Labels and figures with a dotted underline, such as a block’s median fee, Memory Usage or the recommended fee, explain themselves when you hover them. Every widget on the page can also be attached to a question in Ask AI with the element picker, so the answer starts from the figures on your screen.
  • Ticker Pages — the BTC page and its Transactions section
  • Ask AI — questions about what you see, answered in place