0001816431 2024-12-04 2024-12-04 0001816431 qsi:RedeemableWarrantsEachWholeWarrantExercisableForOneShareOfClassACommonStockEachAtAnExercisePriceOf1150PerShareMember 2024-12-04 2024-12-04 0001816431 us-gaap:CommonClassAMember 2024-12-04 2024-12-04 false Quantum-Si Inc 0001816431 NASDAQ NASDAQ 8-K 2024-12-04 DE 001-39486 85-1388175 29 Business Park Drive Branford CT 06405 866 688-7374 false false false false Class A common stock, par value $0.0001 per share QSI Redeemable warrants, each whole warrant exercisable for one share of Class A common stock, each at an exercise price of $11.50 per share QSIAW false