The amount appropriate for incentivizing miners on the network to confirm transactions fluctuates continually as overall network usage and conditions change.
As such, it's important you choose an amount that optimizes the chances that your transaction will confirm on the network, balancing confirmation probability against costs.
The wallet suggests three fee amounts by default to help users determine how much to spend:
Standard (selected by default)
These fee amounts are provided to the Hiro Wallet by the Stacks Blockchain API instance configured under "Change Network" in the settings menu.
The API produces these values using statistical analysis of the last confirmed anchor block seen on the Stacks blockchain by calculating the distribution of fees paid for successfully confirmed transactions in that block.
The "Low" value corresponds to a lower percentile (~10%) of fees paid for successful transactions whereas the "High" value corresponds to a higher percentile (~90%) of fees. The "Standard" value corresponds to the 50th percentile.
While network conditions may have changed significantly since the last anchor block, these value estimates provide users with a historical snapshot that can guide their decision making for transactions they want included in the next block.
Generally speaking, you may want to leave the fees as "Standard" if you don't have a particularly strong or weak preference for how reliably you need your transaction to confirm in the next anchor block.
If you have a particularly strong need for your transaction to confirm in the next anchor block, you may want to select "High" or set a custom fee that's even greater than the "High" value.
If you want to save on fees and have a weak need for your transaction confirm in the next anchor block, you may want to select "Low".
Important: The choice of any amount of fees (however high) does not guarantee confirmation of your transaction in any block.
Additionally, if your transaction doesn't get confirmed in the next anchor block, it may very well get confirmed in a subsequent one. Network conditions may change substantially over the course of the coming blocks in ways that are not anticipated by these suggested values.
You can later use the "Increase fee" feature of the Hiro Wallet to increase the fees of a previously broadcasted transaction, should you set a value that's too low initially.