v3.26.1
FT Vest Nasdaq-100 Dual Directional Buffer ETF - September N-1A Cover
Jun. 09, 2026
Prospectus [Line Items]  
Document Type 485BPOS
Amendment Flag false
Registrant Name First Trust Exchange-Traded Fund VIII
Entity Central Index Key 0001667919
Entity Investment Company Type N-1A
Document Period End Date Jun. 09, 2026
Prospectus Date Jun. 10, 2026