<p>Run the client with the parameter <code>-keypool=10000</code> to generate 10000 keys in your keypool.</p>

<p>Pros: Less backing up</p>

<p>Cons: Your wallet will be bigger (file size) and take maybe a few seconds extra to load</p>

CC BY-SA 3.0
2013-03-29T00:31:12.930Z
Today I learned.
Colin Dean
CC BY-SA 3.0
2013-03-28T19:51:55.393Z
2013-03-28T19:51:55.393Z
Nicolai
<p>That is for Bitcoin-Qt, if you use MultiBit, after you sent money, the change will return to the sending address.</p>

CC BY-SA 3.0
2013-06-26T18:43:45.733Z
2013-06-26T18:43:45.733Z
diyism
<p>A wallet (by default) always contains 100 <strong>unused</strong> keys. Every time the client needs a new key (for a new address, for sending change to, or - in theory - for solo mining payouts), it takes the oldest address from the pool, and creates a fresh one to add.</p>

<p>This just means you need to backup every 100 transactions. No need to switch to a new wallet.</p>

CC BY-SA 3.0
2013-03-29T10:25:38.443Z
When I want new keys, can I just delete old wallet from default location and WILL BE THE NEW ONE GENERATED AUTOMATICALY when turning on the client? And is this option possible?
Comodore
CC BY-SA 3.0
2013-03-29T16:46:16.663Z
If you delete the wallet, a new one will be created yes. But that does mean you lose all your funds, as you lost all old keys. You don't need to worry about this - a wallet always generates new keys when it needs them.
Pieter Wuille
CC BY-SA 3.0
2013-03-30T17:16:38.160Z
And so the key pool is getting constantly bigger? How can I get to know how big is at the moment?
Comodore
CC BY-SA 3.0
2013-03-30T17:29:04.560Z
The keypool always contains 100 future keys. The total number of keys in a wallet (those used + those in the pool) constantly grows indeed, though. I don't think the total number is exposed anywhere, but the getinfo command (RPC or debug window) can tell you the timestamp of the oldest entry in the key pool.
Pieter Wuille
CC BY-SA 3.0
2013-03-28T19:55:13.283Z
2013-03-28T19:55:13.283Z
Pieter Wuille
<p><em>Considering the Bitcoin client for Windows 0.8.1:</em></p>

<p>So the best way (if I have already used up 100 keys) is to send bitcoins to different wallet and then to newly generated one?</p>

<p>When I want new keys, can I just delete old wallet from default location and WILL BE THE NEW ONE GENERATED AUTOMATICALY when turning on the client? </p>

<bitcoin-core><backup><keypool>
Wallet.dat can contain only 100 private keys even if I back up?
Comodore
# Wallet.dat can contain only 100 private keys even if I back up?

(Asked by: username_0 on 2013-03-28)

*Considering the Bitcoin client for Windows 0.8.1:*

So the best way (if I have already used up 100 keys) is to send bitcoins to different wallet and then to newly generated one?

When I want new keys, can I just delete old wallet from default location and WILL BE THE NEW ONE GENERATED AUTOMATICALY when turning on the client?

**Tags:** bitcoin-core, backup, keypool


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## 3 answers

### Answer by username_4 on 2013-03-28. Score: 5 | Accepted answer

A wallet (by default) always contains 100 **unused** keys. Every time the client needs a new key (for a new address, for sending change to, or - in theory - for solo mining payouts), it takes the oldest address from the pool, and creates a fresh one to add.

This just means you need to backup every 100 transactions. No need to switch to a new wallet.

> **Comments:**
> **username_0**: When I want new keys, can I just delete old wallet from default location and WILL BE THE NEW ONE GENERATED AUTOMATICALY when turning on the client? And is this option possible?  
> **username_4**: If you delete the wallet, a new one will be created yes. But that does mean you lose all your funds, as you lost all old keys. You don't need to worry about this - a wallet always generates new keys when it needs them.  
> **username_0**: And so the key pool is getting constantly bigger? How can I get to know how big is at the moment?  
> **username_4**: The keypool always contains 100 future keys. The total number of keys in a wallet (those used + those in the pool) constantly grows indeed, though. I don't think the total number is exposed anywhere, but the getinfo command (RPC or debug window) can tell you the timestamp of the oldest entry in the key pool.  

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### Answer by username_1 on 2013-03-28. Score: 6

Run the client with the parameter `-keypool=10000` to generate 10000 keys in your keypool.

Pros: Less backing up

Cons: Your wallet will be bigger (file size) and take maybe a few seconds extra to load

> **Comments:**
> **username_2**: Today I learned.  

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### Answer by username_3 on 2013-06-26. Score: 0

That is for Bitcoin-Qt, if you use MultiBit, after you sent money, the change will return to the sending address.


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