Bitcoin Forum

Hi.
What purse or service supports the mass sending of bitcoins to multiple bitcoin addresses?
How per one transaction can I send different amounts to different bitcoin wallets?
What purse or service should I use for it?

You can use electrum, and then manually make a transaction, ( if they don't support it but i'm pretty sure they do.) See https://bitcointalk.org/index.php?topic=451707.0

Alternatively  you can use bitcoind and use the "sendmany" Call? Should work aswell.

EDIT: See posts below. Electrum does suppot mass sending just as described in linked thread

Electrum[1].

You can make a pay-to-many transaction by going to "Tools" -> "Pay-to-many" and writing one address per line in the "Pay to" field. If you want to send different amounts per address, simple put a comma and the amount right next to the address.

E.g:

142tAC1CaXe1uwug55Gdm4hBCbDPoJvVu9, 0.1
1P2Ssu7PgGeV1Yxwmc3ejcPZZ7DeaMvBkA, 0.5

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[1] https://electrum.org/#download

Yes, Electrum supports send to many, for as long as I've been using it properly, version 2,6x onwards. Bitcoin core client and blockchain wallets also support the feature. They may be others, but I'm not sure how well they work. My recommendation is always Electrum, but that's personal familiarity.

As far as I know, the number of outputs (or different wallets as you say) is really only limited by your hardware capacities (memory). For my rather average device, I can split to 10 outputs before I notice the wallet starting to hang.

Theoretically, if you could handle much more, you'd still be limited by blocksize... though I can't recall ever seeing a tx with so many inputs or outputs that it would become that big.

Transaction with too many inputs or outputs can be determined as "non standart" transaction, so most of nodes will not relay them and most of miners will not mine it. 

The isStandard() test supports transactions up to 100kb i believe.

Assuming a P2SH/P2PKH transaction is being created, the size (in byte) of a TX with one input and y outputs would be:

For a maximum of 100 kb you could therefore create a (valid) transaction with 3025 outputs.
Correct me if i am wrong, but i didn't found any rule which would lead to such a transaction being non-standard.

It depends on input/otput "weight" also.
I seen many transactions with less than 10 inputs/outputs but with "weight" near 1kB. Hey, in that case 100kb will be near 1000 inputs/outpust but not 3025.
Also, i must check your information about 100kb. Nothing personal. just verification of information  ::)

I was talking about the maximum amount possible.
I took a look and you are right it got changed to a maximum weight of 400.000 [1].
Since non-segwit transaction have a weight of 4*tx_size my calculation still should be correct.

[1] Defined as constant here: https://github.com/bitcoin/bitcoin/blob/3c098a8aa0780009c11b66b1a5d488a928629ebf/src/policy/policy.h#L24 (https://github.com/bitcoin/bitcoin/blob/3c098a8aa0780009c11b66b1a5d488a928629ebf/src/policy/policy.h#L24)
[1] and checked/used here: https://github.com/bitcoin/bitcoin/blob/3c098a8aa0780009c11b66b1a5d488a928629ebf/src/net_processing.cpp#L661-L665 (https://github.com/bitcoin/bitcoin/blob/3c098a8aa0780009c11b66b1a5d488a928629ebf/src/net_processing.cpp#L661-L665)

Thank you all for your answers. It was exhaustive.