The big takeaway is price doesn't determine quality. Walgreens and Adorama Pix had the best quality for around 30 cents per 4x6 print. But Walmart and Amazon had excellent quality for only 9 cents each. At the bottom of CR's ratings, were photos from Mpix - pictures were less saturated, they were less clear and a little bit blurry. But all photos examined were all still better and cheaper than using most home printers.
CR also looked at online editing options like auto-cropping, a feature that should enhance a photo, but -- Some photos were actually cropped so severely that they cut off people's heads.
CR's advice - make sure you review your order closely before you click BUY!
Consumer Reports also says you shouldn't make decisions based solely on how much each print would cost. Be sure to review shipping costs too because they can have a big impact on the final bill. CR suggest checking for free shipping offers or free in-store pickup.