Bitcoin Transactions Stuck? 40K+ Unconfirmed Sparks More Debate


Bitcoin Transactions Stuck? 40K+ Unconfirmed Sparks More Debate

Is your transaction taking a long time to get through? The Bitcoin network is currently showing over 41,000 unconfirmed transactions, reigniting the call for larger block sizes.

Also read: Still No Bitcoin Scaling Solution as April Ends Without SegWit

At press time, the “Unconfirmed Transactions” record on reports 41,211 transactions still awaiting confirmation, with that number wavering in the 40-42,000 range.

Blockchain unconfirmed Bitcoin transactions map

There have been record numbers of bitcoin transactions these past few weeks, as the price soared to over $700 USD, and many users tried to rush their bitcoins to an exchange to take profits in fiat.

Several users have complained their transactions have been stuck for six, even ten hours without confirmation — despite paying the recommended miners’ fee of 0.0002 BTC per transaction, or more.

Today, the average size for a 10-minute block of bitcoin transactions is 960k, an all-time record. Note that this size is an average, not a maximum.

Kaiko - bitcoin average block sizes



New transactions are stored in miners’ “mempool” before being packaged into blocks and validated. This chart shows one mempool recording over 8MB of unconfirmed transactions at several times over the past week:

Kaiko bitcoin mempool chart
chart source:

The current maximum block size is 1MB — a figure many Bitcoin heavyweights say is too low, and a figure that has started a holy war within the bitcoin developer community.

Last month, Bitcoin evangelist Andreas Antonopoulos called for block sizes to be increased before transaction congestion became a problem:

Andreas Antonopoulos block size tweet

Other fierce proponents of larger block sizes are Coinbase CEO Brian Armstrong and Roger Ver, owner of

Roger Ver tweet on larger bitcoin block sizes

Many proposals have been put forward to deal with the problem. The simplest has been to increase the block size to 2MB or more — but opponents say such an increase will cause Bitcoin to centralize, as network nodes with lower bandwidths and storage capacities may drop out of the network.

Rival Bitcoin protocols have also appeared, including Bitcoin XT and Bitcoin Classic, though the original Bitcoin Core seems to be holding its position as the dominant platform.

Other proposals include separating bitcoin transaction signatures from transaction data (“segwit“), or “Sidechains” and “Lightning Network” which process transactions separately and settle them later on the main blockchain.

So far, however, segwit and the Lightning Network remain mostly conceptual — something that does not help Bitcoin’s image when the network suddenly experiences overload, like this week.

Solution Needed Urgently for Scalable Transactions

Inability to process more than seven transactions per second and long transaction confirmation times are often used as arguments against bitcoin use by the legacy financial sector and mainstream media.

No doubt, at a time when the bitcoin price brings ever more media and industry scrutiny, failure to process transactions in a timely manner could show a currency experiment still not ready for mainstream adoption.

Have you experienced lengthy delays or unconfirmed bitcoin payments this month? What’s your preferred solution?

Tags in this story
Andreas Antonopoulos, Bitcoin Block Size, Block Size Debate, Brian Armstrong, Roger Ver

Images courtesy of Weinstock,

Jon Southurst

Jon Southurst has been interested in bitcoin since reading Neal Stephenson's 'Cryptonomicon' in 2012. A long-time tech writer, he has been a regular contributor at CoinDesk and has written for, DeepDotWeb and ancient print publications. He lives on an artificial island in Tokyo.

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