WASHINGTON — Different pharmacies can charge vastly different prices for the same medicine, but there are smartphone apps and websites that comparison shop prices for prescriptions.

“The GoodRX app is the link to a network of pharmacies,” said Carmen Catizone, executive director of the National Association of Boards of Pharmacy.

Similar to what Kayak and Expedia do for flights and hotels, GoodRX searches pharmacies for medicine availability and prices, and provides consumers options to consider. And more.

“If there’s a rebate or a coupon associated with that pharmacy or with that medication, it will also present that to you,” Catizone said.

People who might find this useful include those who don’t have a prescription drug option as part of their insurance plans, or whose insurance plan covers only a certain percentage of the cost of a medication.

“With GoodRX, you’re getting information back from pharmacies that are actually legitimate, so you know that those medications are actually safe and effective,” Catizone said.

The pharmacy board has approved numbers of websites that provide services similar to GoodRx, though not as extensively. For example, LowestMed and ScriptSave WellRx compare prescription prices online or via app. And, sites such as Pharmacy Coupons and PharmaQuotes provide discount coupons.

When shopping for medicine online, Catizone warned that 95 percent of the websites you might encounter are illegal or illegitimate.

“What you need to look for is the ‘dot pharmacy’ domain name,” Catizone said.

Much like you see “.gov” or “.edu,” the “.pharmacy” domain name tells you that the National Association of Boards of Pharmacy has verified and validated the pharmacy.