user14319: Do all bitcoin transaction ids (hashes) have the same length? 
I guess it's defined somewhere here: https://en.bitcoin.it/wiki/Protocol_specification but still I couldn't find it.

user21451: Yes. The transaction ID is SHA256(SHA256(transaction)) as described here and thus always has a length of 256 bits (32 bytes).

14319: <p>Do all bitcoin transaction ids (hashes) have the same length? </p>

<p>I guess it's defined somewhere here: <a href="https://en.bitcoin.it/wiki/Protocol_specification" rel="nofollow">https://en.bitcoin.it/wiki/Protocol_specification</a> but still I couldn't find it.</p>
 21451: <p>Yes. The transaction ID is SHA256(SHA256(transaction)) as described <a href="https://bitcoin.stackexchange.com/questions/2177/how-to-calculate-a-hash-of-a-tx">here</a> and thus always has a length of 256 bits (32 bytes).</p>
