Document and Entity Information - shares	9 Months Ended
	Apr. 30, 2019	Jun. 13, 2019
Document And Entity Information
Entity Registrant Name	PURE BIOSCIENCE, INC.
Entity Central Index Key	0001006028
Document Type	10-Q
Document Period End Date	Apr. 30, 2019
Amendment Flag	false
Current Fiscal Year End Date	--07-31
Entity Reporting Status Current	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business Flag	true
Entity Emerging Growth Company	false
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		75,096,128
Document Fiscal Period Focus	Q3
Document Fiscal Year Focus	2019