<p>There is a maximum standard transaction size since Bitcoin 0.8.2 of 100k per transaction.</p>

<p>There are a number of other limits that influence the validation and propagation of a transaction though. Specifically:</p>

<ul>
<li>A block is <a href="https://github.com/bitcoin/bitcoin/blob/master/src/main.h#L45" rel="nofollow">limited</a> to 20000 signature verifications.</li>
<li>The block itself can't be larger than 1Mb.</li>
<li>The standard Bitcoin client (Bitcoin Core / bitcoind) will refuse to relay transactions flagged as <a href="https://code.google.com/p/bitcoin-wallet/wiki/DustTransactions" rel="nofollow">dust</a>.</li>
<li>Enough fee should be included (0.0001 BTC/kb)</li>
</ul>

CC BY-SA 3.0
2014-05-12T18:33:43.030Z
Thanks for you answer. Could you please prompt me to the documentation (or source code) of the 200 signature validations limit?
Doug Peters
CC BY-SA 3.0
2014-05-12T18:51:25.047Z
My bad, there is no such transaction checksig limit. It's at the block level. Updated my answer.
Matthieu
CC BY-SA 3.0
2018-01-08T14:37:20.620Z
links are 404 and reedirect.

First should probably be something like [this](https://github.com/bitcoin/bitcoin/blob/5961b23898ee7c0af2626c46d5d70e80136578d3/src/validation.cpp#L712) now but more digging needed. Second might be around [here](https://github.com/bitcoin/bitcoin/blob/5961b23898ee7c0af2626c46d5d70e80136578d3/src/policy/policy.cpp#L28).

Fees are more dynamic now. Wouldn't put an aboslute value but rather [this](https://jochen-hoenicke.de/queue/#24h).
Giszmo
CC BY-SA 3.0
2014-05-12T18:25:15.770Z
2014-05-12T18:50:23.113Z
2014-05-12T18:50:23.113Z
Matthieu
<p>Is there a maximum size for any given transaction?</p>

<p>I just created this tx: </p>

<p><a href="http://blockexplorer.com/testnet/tx/194173dcc07b396433d5725abe76d52b10d42ebd3d1d10b465429f87fee12a52" rel="nofollow noreferrer">http://blockexplorer.com/testnet/tx/194173dcc07b396433d5725abe76d52b10d42ebd3d1d10b465429f87fee12a52</a> </p>

<p>and although it seems to get confirmed I would like to know if adding more inputs or outputs (and thus increasing its size) could result in an undesired outcome.</p>

<p>Similar question (that doesn't answer my question, though): <a href="https://bitcoin.stackexchange.com/questions/1823/what-is-the-maximum-size-of-a-transaction">What is the maximum size of a transaction?</a></p>

<raw-transaction><transaction-verification>
Transaction's maximum size
Doug Peters
# Transaction's maximum size

(Asked by: username_0 on 2014-05-12)

Is there a maximum size for any given transaction?

I just created this tx:

<http://blockexplorer.com/testnet/tx/194173dcc07b396433d5725abe76d52b10d42ebd3d1d10b465429f87fee12a52>

and although it seems to get confirmed I would like to know if adding more inputs or outputs (and thus increasing its size) could result in an undesired outcome.

Similar question (that doesn't answer my question, though): [What is the maximum size of a transaction?](https://bitcoin.stackexchange.com/questions/1823/what-is-the-maximum-size-of-a-transaction)

**Tags:** raw-transaction, transaction-verification


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## 1 answers

### Answer by username_1 on 2014-05-12. Score: 5 | Accepted answer

There is a maximum standard transaction size since Bitcoin 0.8.2 of 100k per transaction.

There are a number of other limits that influence the validation and propagation of a transaction though. Specifically:

* A block is [limited](https://github.com/bitcoin/bitcoin/blob/master/src/main.h#L45) to 20000 signature verifications.
* The block itself can't be larger than 1Mb.
* The standard Bitcoin client (Bitcoin Core / bitcoind) will refuse to relay transactions flagged as [dust](https://code.google.com/p/bitcoin-wallet/wiki/DustTransactions).
* Enough fee should be included (0.0001 BTC/kb)

> **Comments:**
> **username_0**: Thanks for you answer. Could you please prompt me to the documentation (or source code) of the 200 signature validations limit?  
> **username_1**: My bad, there is no such transaction checksig limit. It's at the block level. Updated my answer.  
> **username_2**: links are 404 and reedirect.  First should probably be something like [this](https://github.com/bitcoin/bitcoin/blob/5961b23898ee7c0af2626c46d5d70e80136578d3/src/validation.cpp#L712) now but more digging needed. Second might be around [here](https://github.com/bitcoin/bitcoin/blob/5961b23898ee7c0af2626c46d5d70e80136578d3/src/policy/policy.cpp#L28).  Fees are more dynamic now. Wouldn't put an aboslute value but rather [this](https://jochen-hoenicke.de/queue/#24h).  

---

