Whale Transfer Feed Screensaver
The Whale Transfer Feed screensaver scrolls a live feed of unusually large Bitcoin transfers as they enter the mempool, streamed key-less straight from mempool.space. It's free, runs in your browser, and ESC exits.
Live preview
Press ESC to leave fullscreen. Settings are saved in your browser only.
How the Whale Transfer Feed screensaver works
The saver opens a live connection to mempool.space's real-time transaction stream, with no key required.
Every incoming transaction above your chosen threshold scrolls onto the feed with its real value.
Smaller transactions are filtered out so only genuinely large moves surface.
The connection reconnects automatically if the stream drops.
What a large Bitcoin transaction does and does not tell you
When someone broadcasts a Bitcoin transaction it spreads across the network and waits in the mempool until a miner places it in a block. mempool.space, an open-source project, offers a WebSocket API with live subscriptions to mempool and block events, including transactions entering the mempool, which is what lets a display show them before they are confirmed.
Value on this feed is the amount a transaction moves, normally quoted in bitcoin. That has some quirks. Bitcoin uses a UTXO model, where each transaction spends whole earlier outputs and returns any surplus to a change output, so a transfer of a large number of coins can really be a person paying a small amount and sending the rest back to themselves. A big total is not necessarily a big payment.
Equally, nothing in the data identifies the parties. Addresses are pseudonymous strings, and large movements might be an exchange shuffling its own wallets, a custodian consolidating coins or someone moving savings between their own addresses. Calling the moves whale activity is a convenient label, not evidence of intent. Unconfirmed transactions can also be replaced by a higher-fee version, as the mempool.space API’s replace-by-fee (RBF) events reflect, or be dropped, so what appears here may never be confirmed.
A worked example
Set the threshold to 50 BTC and the feed goes quiet for stretches, then a real large transfer appears — an unconfirmed transaction actually broadcasting to the network right now.
Settings & tips
- Alert threshold sets the minimum BTC value to show.
- Accent recolours the feed entries.
- This shows movement, not ownership — a large transfer can be an exchange, a custodian, or an individual.
Frequently asked questions
- Is this live?
- Yes — it streams real unconfirmed transactions the moment they broadcast to the Bitcoin network.
- Is a key needed?
- No. mempool.space's public stream is free and key-less.
- Does it show who sent it?
- No — Bitcoin addresses aren't identities; the feed shows real amounts and addresses, not names.
- Is it free?
- Yes — free, no download, in your browser.
- Can a transaction on this list fail to confirm?
- Yes. It is seen when it enters the mempool, before a miner includes it, and it can be replaced by a higher-fee version or dropped from the mempool.
- Why might a large transfer not mean a sale?
- Many large transactions are internal housekeeping, such as an exchange consolidating wallets. The feed reports amounts moved, not why they moved.
- What is a change output?
- The leftover returned to the sender. Because Bitcoin spends whole outputs, a payment usually includes a second output sending the remainder back to an address the sender controls.