The minimum amount a donor can make to your campaign is $5, €5, £5 or 5kr (depending on your campaign's currency). This minimum donation amount is due to the processing fees applied to each donation.
For example, GoFundMe deducts 5% on all donations. Our US and Canadian payment processor (WePay) also deducts 2.9% + $0.30 on all donations. If someone were to donate $1.99 to you, the fees would be $0.10 + $0.06 + $0.30 = $0.46. That's almost 25% of the total donation!
However, if someone donates $5.00, the fees come out to $0.25 + $0.15 + $0.30 = $0.70, which is only 14% of the total donation. It's a much smaller chunk of the donation and will ultimately help you raise more money.
We have similar fee structures for our international accounts, which you can view here.