<p>Each node on the network has its own mempool. While they are filled with similar transactions, each may have a different size limit or perhaps even custom rules which transactions to retain.</p>

<p><a href="https://i.sstatic.net/m4NNt.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/m4NNt.png" alt="Unconfirmed inputs"></a></p>

<p>In this particular case you can see (figure 1) that there is a <code>(U)</code> shown in both inputs of the transaction. The <code>(U)</code> means that the inputs are created by a transaction that is still unconfirmed.</p>

<p><a href="https://i.sstatic.net/QHTHX.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/QHTHX.png" alt="Address the inputs come from"></a></p>

<p>In fact, when you look at the address that the two inputs were spent to before (figure 2), you'll see that both were created in transactions that only paid 4.4 satoshis per byte whereas the transaction you linked pays 65 satoshis per byte.</p>

<p>I would surmise that the first two transactions that created the inputs might have not been relayed to or were not kept in the mempool of the other blockexplorers. Then, the transaction that you linked would seem invalid to those blockexplorers, because the referenced inputs are not known to it.</p>

<p>You may find this related question interesting: "<a href="https://bitcoin.stackexchange.com/q/46152/5406">How do transactions leave the memory pool?</a>" </p>

CC BY-SA 3.0
2017-02-11T20:59:45.540Z
Oh, I just see that I made German screenshots. "Unbestätigte Transaktion" means unconfirmed transaction as you probably have guessed.
Murch
CC BY-SA 3.0
2017-02-11T21:13:45.433Z
Thanks Murch - I did notice the inputs were unconfirmed but that does not explain why the transaction is not shown on some.
Alex
CC BY-SA 3.0
2017-02-11T21:30:52.150Z
May I just add that I am not seeing the transaction on my node, yet the mempool info shows that it's pretty empty: {
  "size": 12590,
  "bytes": 26220930,
  "usage": 52775360,
  "maxmempool": 300000000,
  "mempoolminfee": 0.00000000
}
Is there anything else I need to do in order for this transaction to be included on my node?
Alex
CC BY-SA 3.0
2017-02-11T21:48:57.710Z
@Alex: Your node would only get the transaction if one of your peers relays it to you. If none of your peers has it, you'll still not see it even if your node would be permissive enough to show it.
Murch
CC BY-SA 3.0
2017-02-11T20:58:14.993Z
2017-02-11T21:13:53.610Z
2017-04-13T12:47:33.583Z
Murch
<p>This is something that has puzzled me for a while and I cannot think of a rational reason for it.
The transaction <code>3361d2484f0566ab13d32f2ab321319945f48eaea1ac2cc9f5a79b40528359c3</code> shows properly on <a href="https://blockchain.info/tx/3361d2484f0566ab13d32f2ab321319945f48eaea1ac2cc9f5a79b40528359c3" rel="nofollow noreferrer">blockchain.info</a> and <a href="https://tradeblock.com/bitcoin/tx/3361d2484f0566ab13d32f2ab321319945f48eaea1ac2cc9f5a79b40528359c3" rel="nofollow noreferrer">tradeblock</a>. </p>

<p>However, I cannot find it either on blockr.io nor blocktrail.com.— I am also running a server to watch transactions and I cannot find this transaction either. Sometimes I can find transactions that do not appear on blockchain so it's quite random. </p>

<p>All servers have many connections so I wonder what could be the issue? Slow network?</p>

CC BY-SA 3.0
2017-02-11T20:42:31.213Z
You should mention in your question that the transaction is unconfirmed. Perhaps you could put screenshots, because the question will likely not be understandable once the transaction confirms.
Murch
CC BY-SA 3.0
2017-02-11T21:10:40.027Z
Nevermind, I took care of that in my answer. ;)
Murch
<unconfirmed-transactions><relay><blockchain-explorer>
Why are some transactions found on some chain explorers but not on others?
Alex
# Why are some transactions found on some chain explorers but not on others?

(Asked by: username_0 on 2017-02-11)

This is something that has puzzled me for a while and I cannot think of a rational reason for it.
The transaction `3361d2484f0566ab13d32f2ab321319945f48eaea1ac2cc9f5a79b40528359c3` shows properly on [blockchain.info](https://blockchain.info/tx/3361d2484f0566ab13d32f2ab321319945f48eaea1ac2cc9f5a79b40528359c3) and [tradeblock](https://tradeblock.com/bitcoin/tx/3361d2484f0566ab13d32f2ab321319945f48eaea1ac2cc9f5a79b40528359c3).

However, I cannot find it either on blockr.io nor blocktrail.com.— I am also running a server to watch transactions and I cannot find this transaction either. Sometimes I can find transactions that do not appear on blockchain so it's quite random.

All servers have many connections so I wonder what could be the issue? Slow network?

**Tags:** unconfirmed-transactions, relay, blockchain-explorer

> **Comments:**
> **username_1**: You should mention in your question that the transaction is unconfirmed. Perhaps you could put screenshots, because the question will likely not be understandable once the transaction confirms.  
> **username_1**: Nevermind, I took care of that in my answer. ;)  

---

## 1 answers

### Answer by username_1 on 2017-02-11. Score: 1 | Accepted answer

Each node on the network has its own mempool. While they are filled with similar transactions, each may have a different size limit or perhaps even custom rules which transactions to retain.

[![Unconfirmed inputs](https://i.sstatic.net/m4NNt.png)](https://i.sstatic.net/m4NNt.png)

In this particular case you can see (figure 1) that there is a `(U)` shown in both inputs of the transaction. The `(U)` means that the inputs are created by a transaction that is still unconfirmed.

[![Address the inputs come from](https://i.sstatic.net/QHTHX.png)](https://i.sstatic.net/QHTHX.png)

In fact, when you look at the address that the two inputs were spent to before (figure 2), you'll see that both were created in transactions that only paid 4.4 satoshis per byte whereas the transaction you linked pays 65 satoshis per byte.

I would surmise that the first two transactions that created the inputs might have not been relayed to or were not kept in the mempool of the other blockexplorers. Then, the transaction that you linked would seem invalid to those blockexplorers, because the referenced inputs are not known to it.

You may find this related question interesting: "[How do transactions leave the memory pool?](https://bitcoin.stackexchange.com/q/46152/5406)"

> **Comments:**
> **username_1**: Oh, I just see that I made German screenshots. "Unbestätigte Transaktion" means unconfirmed transaction as you probably have guessed.  
> **username_0**: Thanks username_1 - I did notice the inputs were unconfirmed but that does not explain why the transaction is not shown on some.  
> **username_0**: May I just add that I am not seeing the transaction on my node, yet the mempool info shows that it's pretty empty: {   "size": 12590,   "bytes": 26220930,   "usage": 52775360,   "maxmempool": 300000000,   "mempoolminfee": 0.00000000 } Is there anything else I need to do in order for this transaction to be included on my node?  
> **username_1**: @username_0: Your node would only get the transaction if one of your peers relays it to you. If none of your peers has it, you'll still not see it even if your node would be permissive enough to show it.  

---

