Yes, online purchases for state residents made during their sales tax holiday will be tax free, even through large online retailers like Amazon. Just make sure you follow your state's guidelines for qualifying items. The time zone of the seller will usually define whether the sale is within the sales tax exemption period.

Shoppers in Ohio can look forward to big savings during this year’s expanded sales tax holiday. It will run 14 days, from Friday, Aug. 1, through Thursday, Aug. 14. Who’s getting an extra paycheck next month The tax holiday allows both online and in-store purchases of most eligible items — up to $500 per item — to be exempted from state sales tax.