v3.25.2
Cover
Jul. 21, 2025
Document Information [Line Items]  
Document Type S-1/A
Amendment Flag true
Amendment Description The Registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this Registration Statement shall thereafter become effective in accordance with section 8(a) of the Securities Act of 1933 or until the Registration Statement shall become effective on such date as the Securities and Exchange Commission acting pursuant to said section 8(a), may determine.
Entity Information [Line Items]  
Entity Registrant Name GigCapital8 Corp.
Entity Central Index Key 0002080019
Entity Primary SIC Number 6770
Entity Tax Identification Number 98-1868645
Entity Incorporation, State or Country Code E9
Entity Filer Category Non-accelerated Filer
Entity Small Business true
Entity Emerging Growth Company true
Entity Ex Transition Period false
Entity Contact Personnel [Line Items]  
Entity Address, Address Line One 1731 Embarcadero Rd
Entity Address, Address Line Two Suite 200
Entity Address, City or Town Palo Alto
Entity Address, State or Province CA
Entity Address, Postal Zip Code 94303
Entity Phone Fax Numbers [Line Items]  
City Area Code 650
Local Phone Number 276-7040
Business Contact [Member]  
Entity Contact Personnel [Line Items]  
Contact Personnel Name Dr. Avi S. Katz
Entity Address, Address Line One 1731 Embarcadero Rd
Entity Address, Address Line Two Suite 200
Entity Address, City or Town Palo Alto
Entity Address, State or Province CA
Entity Address, Postal Zip Code 94303
Entity Phone Fax Numbers [Line Items]  
City Area Code 650
Local Phone Number 276-7040