Apple Inc.’s quick checkout button Apple Pay is finally expanding out of apps and onto the web—but only for consumers who use Apple’s Safari browsers.

Safari and Chrome are the top two mobile internet browsers in the U.S. That means the payment service not being available on Chrome leaves out a good portion of mobile users. Other browsers, such as Firefox, Samsung Internet and Android Browser, make up the remaining share.

However, despite its limited reach, the day Apple made its announcement, retailer 1-800-Flowers.com Inc. said it would incorporate the payment button into its checkout page. E-commerce technology providers Demandware Inc. and IBM Commerce also both announced they will help integrate Apple Pay into their clients’ websites.

“The ability to simplify the checkout process is critical to our success in enhancing the user experience,” says Chris McCann, president and chief operation officer at 1-800-Flowers.

1-800-Flowers.com’s checkout page lists five express checkout options—PayPal, Amex Express Checkout, Visa Checkout, Chase Pay and Buy with MasterPass. Express checkout options allow consumers to save a credit or debit card and check out with fewer clicks. Apple Pay will be the sixth such option. Retailers that add buttons that enable faster checkout to their sites often report lower cart abandonment and increased sales, says Thad Peterson, a senior analyst at consulting firm Aite Group. However, Peterson says a cluttered checkout page can confuse or annoy shoppers.

“Too many [Buy buttons] can make the shopping cart cluttered and potentially increase customer dissonance rather than enhancing sales,” he says. “Merchants need to be smart and offer the payment choices that are most appropriate for their customer demographic.”

What’s unique about Apple Pay on mobile devices is that it requires biometric fingerprint authentication through a service Apple calls Touch ID. Integrating mobile-only biometrics like Touch ID into more payments will make mobile shopping safer, says Matt Schulz, senior industry analyst at CreditCards.com. The Safari-only component to Apple Pay’s expansion to the PC web is likely a strategic move on Apple’s part, Peterson says. He adds he doesn’t see Android, despite being generally more open to adding extensions from other companies than Apple is, as likely to add Apple Pay to its Chrome browser, even if it Apple would allow it.

“I can’t imagine that Android would be willing to accept an Apple Pay function on Chrome, and Apple’s strategy is to deliver an integrated experience so I doubt that they would think it’s in their best interest either,” he says. Apple and Google did not respond to a request for comment.

Apple announced the mobile payment service would work on the web at its Worldwide Developers Conference in San Francisco last week. Previously, Apple Pay was only available as a speedy checkout feature in apps and as a way for consumers to use their iPhones to pay in physical stores. Apple Pay launched in October 2014.

At the conference, Apple listed about 80 companies that have said they will integrate Apple Pay on their website, including Target Corp., Jet.com, Wayfair LLC and JetBlue Airways Corp.

Apple Pay works with credit and debit cards issued by the largest U.S. banks, and the mobile payment service is expanding to other countries, such as Australia, Canada, China, Singapore and the U.K.