<p>At the time of writing, the blockchain is 24 GB in size after 5 years. This is an expansion of 0.12 kilobytes per second. However, this does not represent all of the bandwidth used by the Bitcoin client: </p>

<ol>
<li>The Bitcoin client also relays transactions and blocks it downloads.</li>
<li>The protocol has overhead.</li>
<li>Sometimes the Bitcoin client will download transactions that don't get into the blockchain.</li>
</ol>

<p>I tested the amount of bandwidth that Bitcoin uses by measuring it using <code>bwm-ng</code>, over the course of six and a half hours. I found that it uses 2.1 kilobytes per second, combining upload and download. Over a month, that would add up to 5.5 GB.</p>

<p>Note that my Bitcoin client did not accept incoming connections, which would have changed the result significantly.</p>

<p>This can be an expensive amount of bandwidth. In that circumstance, you can use an alternative, like BlockChain.info, or MultiBit, both of which use almost no bandwidth.</p>

CC BY-SA 3.0
2014-11-10T04:30:44.740Z
The actual download usage of full Bitcoin nodes is somewhat higher because you need to download each transaction twice: once when it is first broadcast and again when it appears in a block. (This needless inefficiency will be fixed in the future.) Also, you download some transactions and other data that doesn't end up in the block chain. Upload bandwidth is much higher than that because you sometimes need to send a transaction or block to each of your peers, and you might even be asked by a peer to send them the entire block chain.
theymos
CC BY-SA 3.0
2014-11-11T06:28:19.160Z
@theymos Thanks for the help improving my answer. Could you look at the edit?
Nick ODell
CC BY-SA 3.0
2014-11-10T02:47:27.780Z
2014-11-11T06:27:41.973Z
2014-11-11T06:27:41.973Z
Nick ODell
<p>Another solution (mostly for future readers of these answers) is getting your Bitcoin data from satellite or DVB broadcasts.</p>

<p>DVB project currently piloting in Finland: <a href="http://kryptoradio.koodilehto.fi/" rel="nofollow">http://kryptoradio.koodilehto.fi/</a></p>

<p>BitSat project, under development: <a href="https://bitcointalk.org/index.php?topic=334701.0" rel="nofollow">https://bitcointalk.org/index.php?topic=334701.0</a></p>

CC BY-SA 3.0
2014-11-10T11:01:01.190Z
2014-11-10T11:01:01.190Z
Jannes
<p>You don't need to run the software 24/7, it just needs to be up-to-date in order to use it when you need to use it, to catch up with a few days worth of blockchain data doesn't take long and wont use much bandwidth.</p>

<p>Each block is 1Mb or less (at the moment) and occurs once every 10 minutes (roughly). So block data is fairly negligible in terms of bandwidth used. </p>

<p>However, as a full node you will also be peer-to-peer transmitting and receiving transactions and also supplying historical blocks to out-of-date peers. It's impossible to predict monthly data transfer because it depends on which peers you are connected to, but it's likely to be several gigabytes per month.</p>

<p>There are also other options instead of running a full node, bitcoin.org details these. e.g. blockchain.info, Hive, Xapo, MultiBit, GreenAddress, etc. You could also rent a cheap VPS server to run a full node on and configure your local node to only connect to that which would save a lot of bandwidth by removing the peer-to-peer data.</p>

CC BY-SA 3.0
2014-11-10T06:35:48.447Z
Note that the cheapest VPS servers may not have enough memory or disk to run a full node.  Also note that VPS providers often charge for bandwidth, at a rate that may be higher than the OP is paying for home Internet.
Nate Eldredge
CC BY-SA 3.0
2014-11-10T05:55:31.683Z
2014-11-10T05:55:31.683Z
George
<p>I understand you have to download the entire blockchain and sync in the beginning but don't you also have to constantly keep the software on if you want to buy/sell stuff, which means more data being downloaded to my personal comp every instant there is a transaction. </p>

<p>If this is true, what is the average amount of data per month being downloaded so that I can use bitcoin. </p>

<p>Also if this is true, why isn't this point highlighted on bitcoin.org, they say you have to initially download the blockchain but not that its constantly going to be downloading data on your comp, data is expensive! </p>

CC BY-SA 3.0
2014-11-10T06:03:50.713Z
Note that there are plenty of other, so called "thin" clients which are perfectly fine if you just want to use Bitcoin, e.g. to buy/sell stuff. Both mobile (all mobile clients are lightweight) as well as desktop clients (e.g. Multibit or Electrum). Furthermore you can also use web wallets, such as coinpunk.com or blockchain.info/wallet and others.
Maǳi Koǌo
CC BY-SA 3.0
2014-11-10T10:58:03.823Z
First: "data is not expensive" is not really true. Both harddisk and bandwidth are cheap and getting cheaper. But maybe you are in a situation where it's not cheap for you, so there are several solutions for that.
Jannes
<blockchain><synchronization>
If using Bitcoin core client am I constantly going to be downloading data from the blockchain?
aza
# If using Bitcoin core client am I constantly going to be downloading data from the blockchain?

(Asked by: username_0 on 2014-11-10)

I understand you have to download the entire blockchain and sync in the beginning but don't you also have to constantly keep the software on if you want to buy/sell stuff, which means more data being downloaded to my personal comp every instant there is a transaction.

If this is true, what is the average amount of data per month being downloaded so that I can use bitcoin.

Also if this is true, why isn't this point highlighted on bitcoin.org, they say you have to initially download the blockchain but not that its constantly going to be downloading data on your comp, data is expensive!

**Tags:** blockchain, synchronization

> **Comments:**
> **username_1**: Note that there are plenty of other, so called "thin" clients which are perfectly fine if you just want to use Bitcoin, e.g. to buy/sell stuff. Both mobile (all mobile clients are lightweight) as well as desktop clients (e.g. Multibit or Electrum). Furthermore you can also use web wallets, such as coinpunk.com or blockchain.info/wallet and others.  
> **username_2**: First: "data is not expensive" is not really true. Both harddisk and bandwidth are cheap and getting cheaper. But maybe you are in a situation where it's not cheap for you, so there are several solutions for that.  

---

## 3 answers

### Answer by username_3 on 2014-11-10. Score: 1 | Accepted answer

At the time of writing, the blockchain is 24 GB in size after 5 years. This is an expansion of 0.12 kilobytes per second. However, this does not represent all of the bandwidth used by the Bitcoin client:

1. The Bitcoin client also relays transactions and blocks it downloads.
2. The protocol has overhead.
3. Sometimes the Bitcoin client will download transactions that don't get into the blockchain.

I tested the amount of bandwidth that Bitcoin uses by measuring it using `bwm-ng`, over the course of six and a half hours. I found that it uses 2.1 kilobytes per second, combining upload and download. Over a month, that would add up to 5.5 GB.

Note that my Bitcoin client did not accept incoming connections, which would have changed the result significantly.

This can be an expensive amount of bandwidth. In that circumstance, you can use an alternative, like BlockChain.info, or MultiBit, both of which use almost no bandwidth.

> **Comments:**
> **username_4**: The actual download usage of full Bitcoin nodes is somewhat higher because you need to download each transaction twice: once when it is first broadcast and again when it appears in a block. (This needless inefficiency will be fixed in the future.) Also, you download some transactions and other data that doesn't end up in the block chain. Upload bandwidth is much higher than that because you sometimes need to send a transaction or block to each of your peers, and you might even be asked by a peer to send them the entire block chain.  
> **username_3**: @username_4 Thanks for the help improving my answer. Could you look at the edit?  

---

### Answer by username_2 on 2014-11-10. Score: 0

Another solution (mostly for future readers of these answers) is getting your Bitcoin data from satellite or DVB broadcasts.

DVB project currently piloting in Finland: <http://kryptoradio.koodilehto.fi/>

BitSat project, under development: <https://bitcointalk.org/index.php?topic=334701.0>


---

### Answer by username_5 on 2014-11-10. Score: 0

You don't need to run the software 24/7, it just needs to be up-to-date in order to use it when you need to use it, to catch up with a few days worth of blockchain data doesn't take long and wont use much bandwidth.

Each block is 1Mb or less (at the moment) and occurs once every 10 minutes (roughly). So block data is fairly negligible in terms of bandwidth used.

However, as a full node you will also be peer-to-peer transmitting and receiving transactions and also supplying historical blocks to out-of-date peers. It's impossible to predict monthly data transfer because it depends on which peers you are connected to, but it's likely to be several gigabytes per month.

There are also other options instead of running a full node, bitcoin.org details these. e.g. blockchain.info, Hive, Xapo, MultiBit, GreenAddress, etc. You could also rent a cheap VPS server to run a full node on and configure your local node to only connect to that which would save a lot of bandwidth by removing the peer-to-peer data.

> **Comments:**
> **username_6**: Note that the cheapest VPS servers may not have enough memory or disk to run a full node.  Also note that VPS providers often charge for bandwidth, at a rate that may be higher than the OP is paying for home Internet.  

---

