Take note that each node has its own mempool.
Your transaction being local in electrum means that it exists in the wallet file, but the server you are connected to doesn't have it in their mempool.
It's possible that your transaction exists in ViaBTC mempool, although it's not displayed in electrum.


Sometimes, it's helpful to rebroadcast a transaction and sometimes it's not.


Let's say I have made transaction more than 14 days ago and many nodes have dropped my transaction from their mempool.
If I broadcast my transaction, many of those nodes will receive my transaction and put it in their mempool again. In this way I can make the transaction have a better propagation.

If some nodes dropped my transaction due to their size limit and their purging fee rate is still higher than the fee rate of my transaction, I wouldn't change anything with rebroadcasting my transaction.


As suggested by Charles-Tim above, resubmit your transaction to ViaBTC free accelerator.
Do that even if there is no remaining free hourly transaction.

If they don't have your transaction in their mempool at all, you should see a message saying transaction doesn't exist.

Bots are again abusing ViaBTC free accelerator.
In the last block mined by ViaBTC, the minimum required fee rate for getting confirmation normally was more than 80 sat/vbyte. ViaBTC included 165 one input - one output ordinal transactions that paid 23-24 sat/vbyte each.

No, if you want your blocks to be accepted by others.

Let's say the most recent block is block number 823,881 and you (the attacker) want to replace that with a new block.
To do so, you must mine the block number 823,881 while other miners are trying to mine the block number 823,882. To be successful, you need a big hash power, so that you are fast enough and can build the chain with the most work.

If you want to replace the last two blocks, you have to start from block number 823,880 and the chance of being successful would become much smaller.
The probability of success decreases exponentially, if you want more blocks to be replaced in the blockchain.


Note that given the big total hash rate of the network, even replacing a single block is almost impossible.

I did the same and was able to submit a transaction to their free accelerator successfully.
I even submitted an ordinal transaction with the same pattern as ordinal transactions submitted by the bots in the past days and it worked. (I am sorry I helped a network spammer)

I don't know whether bots stopped abusing ViaBTC free accelerator or it's ViaBTC that stopped them somehow, but the requirements seem to be still same as before.

If you go to "Receive" tab and create a request, you can be sure that you haven't given that address to someone else before. This is useful for protecting your privacy.

With using the "Receive", you can also set an expiry time for your request and add a description. In this way, you can know which address you gave to whom and whether the payment has been made before the deadline or not.

It may worth mentioning that the fee they charge you for accelerating your transaction doesn't depend on the amount of bitcoin you send.


ViaBTC was the only working free accelerator until bots made it useless.
All other websites that claim to accelerate transactions freely, are either scammers or just rebroadcast transactions.

Even bitcoin.org itself recommends checking bitcoincore.org to make sure you are downloading the latest version.

It seems that they stop accepting new transactions once they reach a certain size of transactions waiting to be mined freely.
Of course, nothing has been mentioned on their website and I don't know the exact amount. I just know that it should happen very rarely. ViaBTC has around 10% of the total hash rate and it's estimated that they mine 1 block in every ~ 100 minutes on average.


They could accept more transactions, but it seems that they don't allocate the space of each block more than a certain amount to freely accelerated  transactions.

ViaBTC didn't mine any block between 00:00  and 09:05 UTC and I think they stopped accepting new transactions once they reached a certain size of transactions waiting to be mined freely.

I made a post about this in another thread.
Re: ViaBTC offers no more free TX acceleration?

Yes, they are bypassing the captcha.
Bots solve ViaBTC captcha faster than humans.


I just checked that and it's still displaying 19 remaining hourly free transactions.

ViaBTC hasn't mined any block in the past 9 hours.
I guess they won't accept any new transaction for free acceleration until they mine a new block and include the transactions they have received in the past 9 hours.


Edit:
It seems that my guess was correct.
ViaBTC just mined a block and they accepted more transactions for free acceleration after that.
The number of remaining hourly free transactions is now zero.

They are still accelerating 100 transactions per hour freely.
The problem is that ordinal scammers are abusing ViaBTC free accelerator with their bots and don't allow humans to submit their transactions.

If you check the last blocks mined by ViaBTC, you will see that they have included many low fee transactions.

Read the post I made in another thread.

Can I ask you what exactly you worry about? Do you think your wallet may be compromised?

Note that you can replace a transaction with a new one only if you have the private key of one of receiving addresses. If your wallet is compromised, your fund can be stolen right now.
And even if you broadcast a RBF-disabled transaction, as long as it's unconfirmed, anyone who has access to your private key may be able to replace that with a new one.

I think they do.

Here are the latest two blocks mined by ViaBTC. Transactions are sorted by their fee rate in ascending order.
(Times are in UTC.)

• 823055 (19:31)
• 823066 (22:01)

Just visit the above links and see how many low fee transactions they have included.


According to above times, ViaBTC should have accelerated 300 transactions freely in block number 823066.
Let's check if they did so.


The minimum required fee rate for getting confirmation in block number 823066 was around 100 satoshi. ViaBTC included 312 transactions with the fee rate of less than 90 sat/vbyte. Click here to see all those transactions.
10 out of those 312 transactions were confirmed with CPFP and that means that 302 transactions were accelerated by ViaBTC. All those 302 transactions meet ViaBTC free accelerator requirements.

The problem is how ViaBTC free accelerator is being abused by bots. 294 out of 302 transactions are related to ordinals. They are all 1 input - 1 output transactions paying 23 sat/vbyte.

Username: hosseinimr93
Segwit Bitcoin address: bc1qq469jmsttgwju04fkzft8fhh7lged0r2hgn7xm

Again, what matters is the fee rate and that's what miners prioritize transactions based on.
The total fee you pay for a transaction is equal to virtual size of transaction (in vbyte) multiplied by fee rate (in sat/vbyte) and it doesn't matter how much bitcoin you send. The (virtual) size of the transaction depends on number of inputs and outputs and addresses types.


Let's say you want to make a transaction including 100 legacy inputs and 1 output. Your transaction would be around 14,700 vbyte in (virtual) size.
If you are not in a hurry and you make the transaction with the fee rate of only 20 sat/vbyte, it would cost you more than $120 worth of bitcoin.

It's possible that most of the nodes drop your transaction from their mempool, but there is no guarantee that it won't be confirmed.
As long as there is no other confirmed transaction invalidating that transaction, there's a chance that the transaction is confirmed.

If you have broadcasted a transaction and you want to make sure that it won't be confirmed, you must create a new transaction using the same input and invalidate that.
Provided that the transaction is still valid, it may be confirmed one day even if you broadcasted it months ago and your wallet doesn't show it anymore.

If they change the captcha, those spammers will probably find a way to bypass the captcha again.
They may add an extra requirement and not allow transactions that create output worth less than a certain amount to be submitted to their free accelerator.

The sad news is that those bots have been created by ordinal scammers.

I just checked one of the blocks mined by ViaBTC recently on blockchair.com and sorted the transactions by their fee rate. (Click here.)
In block number 822736, the required fee rate to get confirmation normally was 72 sat/vbyte. ViaBTC included 110 transactions with the fee rate of less than 70 sat/vbyte. 95 of them were 1 input - 1 output transactions sending 294, 330 or 546 satoshi paying 23 sat/vbyte.

I checked the 15 other transactions one by one. 11 of them were larger than 500 bytes in size and it's not possible that they have been submitted to ViaBTC free accelerator. 2 out of the 4 remaining transactions were confirmed with doing CPFP. In block 822,736 which was mined ViaBTC, there were only 2 normal transactions that may have been confirmed with the help of their free accelerator.

Making another withdrawal from cashapp doesn't affect your unconfirmed transaction and that's useless.

Nothing will change after 14 days.
Many nodes will still keep the transaction in their mempool and cashapp may rebroadcast the transaction.


Do you have control over the receiving address? If so, you can do CPFP.
CPFP means spending the fund received in the unconfirmed transaction with high fee in a new transaction, so that miners include both transactions in the same block.

If you are referring to an individual private key, you can derive three types of addresses.

Select "Import addresses or private keys" when creating a new wallet and add a prefix to specify the address type.

Use "p2pkh" for generating a legacy address.
Use "p2wpkh-p2sh" for generating a nested segwit address.
Use "p2wpkh" for generating a native segwit address.

For example, if you want to generate a native segwit address, you should enter your private key as follows.




To be more accurate, this command increases the gap limit.
For example, if you set the gap limit to 200, electrum will generate more and more addresses and display their transactions history until it reaches 200 consecutive unused addresses.



new19980, you can also use the following command to generate more addresses without increasing the gap limit.

This command generates 50 more addresses without increasing the gap limit.