v3.26.1
Label Element Value
Risk/Return: oef_RiskReturnAbstract  
Document Type dei_DocumentType 485BPOS
Document Period End Date dei_DocumentPeriodEndDate Feb. 28, 2026
Registrant Name dei_EntityRegistrantName MFS® ACTIVE EXCHANGE TRADED FUNDS TRUST
Entity Central Index Key dei_EntityCentralIndexKey 0002018846
Amendment Flag dei_AmendmentFlag false
Document Creation Date dei_DocumentCreationDate Aug. 27, 2026
Document Effective Date dei_DocumentEffectiveDate Aug. 31, 2026
Entity Investment Company Type dei_EntityInvCompanyType N-1A
Prospectus Date oef_ProspectusDate Aug. 31, 2026
MFS Active Short Duration Income ETF | MFS Active Short Duration Income ETF  
Risk/Return: oef_RiskReturnAbstract  
Trading Symbol dei_TradingSymbol MFSD
MFS Active Short Muni Bond ETF | MFS Active Short Muni Bond ETF  
Risk/Return: oef_RiskReturnAbstract  
Trading Symbol dei_TradingSymbol MFSX