Summary of significant accounting policies - Prepayments (Details) - USD ($)	12 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2024
Summary of significant accounting policies
Impairment loss of prepayments	$ 513,254	$ 0	$ 117,000

Amount of expense (reversal of expense) for expected credit loss on prepayments.

No definition available.

Name:	btog_PrepaymentsCreditLossExpenseReversal
Namespace Prefix:	btog_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration