user117527: I would like the create a transaction without broadcasting it to the network.

user26873: You can do so by building a raw transaction in the debug console (but be very careful, you can lose your funds if you're not experienced).
When building raw transactions you can think of it in three basic steps.

Create Raw Transaction createrawtransaction (https://bitcoincore.org/en/doc/0.18.0/rpc/rawtransactions/createrawtransaction/)
Sign Raw Transaction signrawtransactionwithkey (https://bitcoincore.org/en/doc/0.18.0/rpc/rawtransactions/signrawtransactionwithkey/)
Broadcast sendrawtransaction (https://bitcoincore.org/en/doc/0.18.0/rpc/rawtransactions/sendrawtransaction/)

The hexadecimal response you receive after signing (step 2) is your fully signed transaction.

user24925: testmempoolaccept is a RPC which lets you dry-run submitting a transaction like sendrawtransaction, without actually pushing the transaction into your mempool or to the p2p network. Both function identically other than the final operation of broadcasting, so error messages can be considered equal.

117527: <p>I would like the create a transaction without broadcasting it to the network.</p>
 26873: <p>You can do so by building a raw transaction in the debug console (but be very careful, you can lose your funds if you're not experienced).</p>
<p>When building raw transactions you can think of it in three basic steps.</p>
<ol>
<li>Create Raw Transaction <code>createrawtransaction</code> (<a href="https://bitcoincore.org/en/doc/0.18.0/rpc/rawtransactions/createrawtransaction/" rel="nofollow noreferrer">https://bitcoincore.org/en/doc/0.18.0/rpc/rawtransactions/createrawtransaction/</a>)</li>
<li>Sign Raw Transaction <code>signrawtransactionwithkey</code> (<a href="https://bitcoincore.org/en/doc/0.18.0/rpc/rawtransactions/signrawtransactionwithkey/" rel="nofollow noreferrer">https://bitcoincore.org/en/doc/0.18.0/rpc/rawtransactions/signrawtransactionwithkey/</a>)</li>
<li>Broadcast <code>sendrawtransaction</code> (<a href="https://bitcoincore.org/en/doc/0.18.0/rpc/rawtransactions/sendrawtransaction/" rel="nofollow noreferrer">https://bitcoincore.org/en/doc/0.18.0/rpc/rawtransactions/sendrawtransaction/</a>)</li>
</ol>
<p>The hexadecimal response you receive after signing (step 2) is your fully signed transaction.</p>
 24925: <p><code>testmempoolaccept</code> is a RPC which lets you dry-run submitting a transaction like <code>sendrawtransaction</code>, without actually pushing the transaction into your mempool or to the p2p network. Both function identically other than the final operation of broadcasting, so error messages can be considered equal.</p>
