_ Here's how it works: Anybody can ask a question Anybody can answer The best answers are voted up and rise to the top up vote down vote favorite 3 I see from the source code (script.cpp) that there is an upper limit in the script size.It there any other limit to avoid a single transaction preventing other transactions of smaller sizes to get into a block?How is this kind of attack prevented?I've read in CTransaction::AcceptToMemoryPool the line: if .... ::GetSerializeSize(*this, SER_NETWORK) < 100) return error("...");Does this line means that the maximum transaction size is 100 bytes?transactions up vote 6 down vote If there is a max transaction size it is much higher than 100 bytes.Not sure what that snippet is refering to but the average transaction is closer to ~300 bytes looking at the average # of transactions and block size for last 1000 blocks.What limits transaction size is cost.As transaction size (of all transactions awaiting next block) increases the min required fee increases non-linearly.

0.01 BTC fee per kilobyte of transaction, but: If the blocksize (size of all transactions currently waiting to be included in a block) is less than 27 kB, transactions are free.If the blocksize is more than 250 kB, transactions get increasingly more expensive as the blocksize approaches the limit of 500 kB.Sending a transaction when the blocksize is 400 kB will cost 5 times the normal amount; sending when it's 499 kB will cost 500x, etc. https://en.bitcoin.it/wiki/Transaction_fees So you could make a 500KB transaction but the required minimum fee would be 5BTC.The developers have indicated they intend to change transaction fee rules in the future but given block space is a valuable commodity any new rules are likely to be constructed to encourage (via larger fees) smaller transaction sizes.up vote 9 down vote The maximum transaction size is the size of the block.if (::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION) > MAX_BLOCK_SIZE) return state.DoS(100, error("CheckTransaction(): size limits failed"), REJECT_INVALID, "bad-txns-oversize"); Transactions larger than 100 kilobytes are non-standard.

Source 2. static const unsigned int MAX_STANDARD_TX_SIZE = 100000; ... unsigned int sz = tx.GetSerializeSize(SER_NETWORK, CTransaction::CURRENT_VERSION); if (sz >= MAX_STANDARD_TX_SIZE) { reason = "tx-size"; return false; } Your Answer Sign up or log in Sign up using Google Sign up using Email and Password Post as a guest Name Email discard By posting your answer, you agree to the privacy policy and terms of service.Browse other questions tagged transactions or ask your own question.Jump to: , The maximum transaction rate is the block size limit divided by the average transaction size.The block size limit is well known, 1MB, however the average transaction size isn't.Here we'll look at what influences that size.The minimum sized transaction type[1] is the OP_CHECKSIG transaction: Each transaction input requires at least 41 bytes for the previous transaction reference and other headers and each transaction output requires an additional 9 bytes of headers.

Finally every transaction has a header at least 10 bytes long.Added up we get 166 bytes for the minimum-sized Bitcoin transaction.For 1MB (1,000,000 byte) blocks this implies a theoretical maximum rate of 10tx/s.damnit maurie bitcoinHowever change complicates the situation.bitcoin lernenIt isn't always possible for a client to find a transaction input of the size required.bitcoin leyesThus client software will included additional outputs to themselves for the change, and similarly they will include additional inputs to collect change outputs together when no one output is large enough.Users with large wallets, in particular eWallets such as Instawallet or large exchanges like Mt.Gox are most likely to be able to find transaction outputs of a suitable size for any given payment.

It's conceivable that if transaction fees are high enough in the future users who trust each other may get together to use each others wallets to make payments as a way to avoid transaction fees, with the balances settled periodically by some other means.Contents 1 2 3 4 Users can also combine their transactions to make them slightly smaller, and possibly improve privacy.A transaction is invalid until every transaction input is signed for, thus multiple users can create a joint transaction with no risk of their funds being stolen.This reduces average transaction size by 10 bytes, the size of the per-transaction header.Using this technique aggressively results in 156 byte average transactions, or 10.7tx/s.A reasonable, conservative, assumption is to assume that every transaction requires two outputs, including change, and two inputs, consuming change.Assuming that trust-free combining is not used gives us 322 byte transactions, or 5.2tx/s.Actual real-world rates will likely be somewhere between those numbers, although equally rates may be less as well if multi-signature transactions are become popular; the figure 7tx/s is commonly quoted as a 'ball-park' approximation in discussions of the blocksize limit.

Numbers discussed here apply to the bitcoin blockchain and are no hard limits to the bitcoin system in a broader sense.Off chain transactions, most notably transaction channels allow arbitrary transaction rates with instant, off the chain (added privacy), secure micro-transactions._ Here's how it works: Anybody can ask a question Anybody can answer The best answers are voted up and rise to the top up vote 4 down vote favorite Is there a maximum size for any given transaction?I just created this tx: /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?raw-transaction transaction-verification up vote 5 down vote There is a maximum standard transaction size since Bitcoin 0.8.2 of 100k per transaction.