How to notice a flash Bitcoin

[Kalson9]

Actually a transfer of Bitcoin to another wallet is known as transaction and once the Bitcoin is fake it won't have any confirmation from the network and once is a fake Bitcoin transaction it won't include the transaction fee.
That alone shows that is being loaded
And once again after is received in your wallet wait for 20 minutes before re-checking your blockchain wallet.

[un_rank]

You used words I have not come across around.
A bitcoin transaction can be sent out by someone with a low transaction fee [below the feerate at that time]. With such low fee, the bitcoins might not get confirmed by miners and can still be double spent.
Wait for 1 confirmation, or more like 2 or 3, to be sure the bitcoins have been received into your wallet.

[khaled0111]

once the Bitcoin is fake it won't have any confirmation from the network and once is a fake Bitcoin transaction it won't include the transaction fee.

There is no such thing as fake bitcoin or fake transaction. The scam scheme you are talking about consists of sending bitcoin (real bitcoin) to your wallet but the scammer cancels the transaction while it's still unconfirmed. And for this to work, the scmmer needs to set a very small fee rate to guarantee the transaction will remain unconfirmed as long as possible.

In order to not fall for this scam, only consider transactions with 1+ confirmations (depending on the transacted amount) as final. Any unconfirmed balance is not yours, yet.
You can also disable the feature to show unconfirmed balance from your wallet settings (if it supports this feature).

[Kalson9]

You used words I have not come across around.
A bitcoin transaction can be sent out by someone with a low transaction fee [below the feerate at that time]. With such low fee, the bitcoins might not get confirmed by miners and can still be double spent.
Wait for 1 confirmation, or more like 2 or 3, to be sure the bitcoins have been received into your wallet.

You see you said Bitcoin transaction that is if is real Bitcoin that will involve transaction fee.

[Bitcoin_Arena]

And once again after is received in your wallet wait for 20 minutes before re-checking your blockchain wallet.

Most importantly, do not use Blockchain wallet. So many people have been tricked in the past thinking they have already received Bitcoins in their Blockchain wallet even before the transaction is confirmed, only for it to be double spent.

Use better noncustodial wallets like electrum

[BitMaxz]

You see you said Bitcoin transaction that is if is real Bitcoin that will involve transaction fee.

What exactly do you mean by fake Bitcoin? Actually, there are some fake Bitcoin it was in the ETH network which is wrapped BTC.

If you were talking about zero fees then no pool will include your transaction to confirm it will be stuck on the mempool unless if you own a miner and are mining on f2pool you can request to them to include your transaction to mine.

And I think doublespend is what exactly you talking about you receive a zero fee transaction and then it stuck unconfirmed and the sender made another transaction with a fee to a different address that you didn't own and the BTC you received never confirmed.

[Pokapoka124]

Actually a transfer of Bitcoin to another wallet is known as transaction and once the Bitcoin is fake it won't have any confirmation from the network and once is a fake Bitcoin transaction it won't include the transaction fee.
That alone shows that is being loaded
And once again after is received in your wallet wait for 20 minutes before re-checking your blockchain wallet.

There's no such thing as fake Bitcoin. You can't print or create new or fake bitcoins, there is a limited supply. The scammers take advantage of replace by fee which allows the person to double spend the transaction. You can always trust the Blockchain to give you an accurate result, use a Blockchain explorer like Blockchair to monitor your transactions and only pay when you have received at least 3 confirmations.

[pooya87]

You can always trust the Blockchain to give you an accurate result, use a Blockchain explorer like Blockchair to monitor your transactions and only pay when you have received at least 3 confirmations.

Using block explorers is never safe. For starters they are the enemy of your privacy since they record your activity and link it to your IP and possibly your identity. Additionally many of them have bugs that could be exploited if you are checking validity of a transaction or its confirmation.
You should stick to a trusted wallet that directly connects to the bitcoin network either as a full node or an SPV client connecting to a full node.

[Charles-Tim]

Actually a transfer of Bitcoin to another wallet is known as transaction and once the Bitcoin is fake it won't have any confirmation from the network and once is a fake Bitcoin transaction it won't include the transaction fee.

In this regard, they are real bitcoin, but just that the scammer double-spent the coin by replacing the transaction with a higher fee and change your address to his own address.

And once again after is received in your wallet wait for 20 minutes before re-checking your blockchain wallet.

You do not have to wait 20 minutes, and you can wait longer, it depends on how congested the mempool is and when the transaction is confirmed. Once the transaction is confirmed, the coin can no more be double-spent by the scammer.

Using block explorers is never safe.

That is true, since I have been using Electrum, I do not have to make use of any block explorer, all can be seen on Electrum directly. But there are sometimes I just wanted to check txid or address of an unknown person which I am not the sender or receiver, and not running full node, so in this case, I just connect Tor to check that on blockchain explorer as I can not use light client for it.