<p>Transactions are broadcasted by anyone in the system and at random intervals. Which transactions, of all the ones broadcasted, are included is very dependent on the miner, as he/she is the one who groups them up and includes them in the block. As Nate noted below, there is also a 1MB block size limit which limits how many transactions can be included in a block. This limit is to prevent huge blocks that clog the network and may be removed if the number of transactions in the network ever grows such that the limit is a serious factor.</p>

<p>Good miners accept all transactions with the standard 0.0001 BTC fee (which is mainly a spam prevention measure). Bad miners are selfish and avoid including transactions to decrease their propogation time. For example, look at <a href="https://blockchain.info/block-height/315076" rel="noreferrer">this block</a> to see an example where a miner didn't include any transactions except for their own reward transaction. </p>

<p>If you look at <a href="https://blockchain.info/" rel="noreferrer">https://blockchain.info/</a> then you can see how many transactions are included in each block. </p>

<p>As far as priority goes, again it depends on the miner, but in general miners like bigger fees and smaller transactions and may prioritize them that way.</p>

CC BY-SA 3.0
2014-08-13T13:45:31.090Z
This is a nice answer, but it should also mention the block size limit which seems to be relevant to the question.
Nate Eldredge
CC BY-SA 3.0
2014-08-13T14:01:30.080Z
Thanks, good suggestion Nate. I edited my comment to include a comment about the 1MB block size limit.
morsecoder
CC BY-SA 3.0
2014-08-14T08:43:01.297Z
Thanks Stephen.
Same broadcast transaction(ex. T1) can be processed by multiple miners at same time?
Tushar
CC BY-SA 3.0
2014-08-14T14:06:44.817Z
Yes, definitely. Miners are continually trying to include transactions into their block and typically are working with the same (or very close to) transaction set. And we want it this way so that if you make a transaction and broadcast it, it is included into a block no matter who solves the next block. Did these answers answer your question?
morsecoder
CC BY-SA 3.0
2014-09-26T18:10:35.890Z
Tushar, if this answer helped, then make sure you mark it as correct so people looking for the answer to the same question can see that this was the answer that helped you. If you would like more clarification then just ask!
morsecoder
CC BY-SA 4.0
2018-05-12T06:01:18.533Z
@StephenM347 Wait, how does Bitcoin deter miners from not including transactions if they can be rewarded without transactions? Isn't it more beneficial to just ignore all transactions, so you don't have to wait for the block to fill up and start your hash solving right away?
Strawberry
CC BY-SA 4.0
2018-05-27T07:13:02.677Z
@Strawberry Miners don't have to wait :) [Here](https://blockchain.info/unconfirmed-transactions) you can view currently unconfirmed transactions. The moment a user wants to start trying to build a block, he just has to pull current pool and start hashing it, trying out random nonces.
Jakub Tustanowski
CC BY-SA 3.0
2014-08-13T13:33:16.957Z
2014-08-13T14:00:46.123Z
2014-08-13T14:00:46.123Z
morsecoder
<p>Block is collection of transactions.Who can decide Number of transactions per block? and How transactions are selected in block?</p>

<p>and How does the priority works for fee transactions?</p>

<p>Thanks </p>

CC BY-SA 3.0
2015-05-08T10:21:36.783Z
Please only ask one question per post. The first question is a duplicate of [What is the number of transactions in a block?](http://bitcoin.stackexchange.com/q/10457/5406), the second is a duplicate of [How do miners select which transactions to include in a block](http://bitcoin.stackexchange.com/q/7311/5406), the third is a duplicate of [How does the standard client prioritize transactions?](http://bitcoin.stackexchange.com/q/3409/5406)
Murch
<transactions><transaction-fees><block>
How many transactions in One Block?
Tushar
# How many transactions in One Block?

(Asked by: username_0 on 2014-08-13)

Block is collection of transactions.Who can decide Number of transactions per block? and How transactions are selected in block?

and How does the priority works for fee transactions?

Thanks

**Tags:** transactions, transaction-fees, block

> **Comments:**
> **username_1**: Please only ask one question per post. The first question is a duplicate of [What is the number of transactions in a block?](http://bitcoin.stackexchange.com/q/10457/5406), the second is a duplicate of [How do miners select which transactions to include in a block](http://bitcoin.stackexchange.com/q/7311/5406), the third is a duplicate of [How does the standard client prioritize transactions?](http://bitcoin.stackexchange.com/q/3409/5406)  

---

## 1 answers

### Answer by username_2 on 2014-08-13. Score: 17

Transactions are broadcasted by anyone in the system and at random intervals. Which transactions, of all the ones broadcasted, are included is very dependent on the miner, as he/she is the one who groups them up and includes them in the block. As username_3 noted below, there is also a 1MB block size limit which limits how many transactions can be included in a block. This limit is to prevent huge blocks that clog the network and may be removed if the number of transactions in the network ever grows such that the limit is a serious factor.

Good miners accept all transactions with the standard 0.0001 BTC fee (which is mainly a spam prevention measure). Bad miners are selfish and avoid including transactions to decrease their propogation time. For example, look at [this block](https://blockchain.info/block-height/315076) to see an example where a miner didn't include any transactions except for their own reward transaction.

If you look at <https://blockchain.info/> then you can see how many transactions are included in each block.

As far as priority goes, again it depends on the miner, but in general miners like bigger fees and smaller transactions and may prioritize them that way.

> **Comments:**
> **username_3**: This is a nice answer, but it should also mention the block size limit which seems to be relevant to the question.  
> **username_2**: Thanks, good suggestion username_3. I edited my comment to include a comment about the 1MB block size limit.  
> **username_0**: Thanks Stephen. Same broadcast transaction(ex. T1) can be processed by multiple miners at same time?  
> **username_2**: Yes, definitely. Miners are continually trying to include transactions into their block and typically are working with the same (or very close to) transaction set. And we want it this way so that if you make a transaction and broadcast it, it is included into a block no matter who solves the next block. Did these answers answer your question?  
> **username_2**: username_0, if this answer helped, then make sure you mark it as correct so people looking for the answer to the same question can see that this was the answer that helped you. If you would like more clarification then just ask!  
> **username_4**: @StephenM347 Wait, how does Bitcoin deter miners from not including transactions if they can be rewarded without transactions? Isn't it more beneficial to just ignore all transactions, so you don't have to wait for the block to fill up and start your hash solving right away?  
> **username_5**: @username_4 Miners don't have to wait :) [Here](https://blockchain.info/unconfirmed-transactions) you can view currently unconfirmed transactions. The moment a user wants to start trying to build a block, he just has to pull current pool and start hashing it, trying out random nonces.  

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