Apple now faces challenges to its WebKit browser requirement in three jurisdictions, as authorities around the globe try to jumpstart competition in the mobile software industry.
Japan last week published legal guidance for its recent smartphone competition law, the Mobile Software Competition Act, indicating that restrictions like Apple’s WebKit mandate for browsing apps will not be allowed.
Apple’s requirement, spelled out in section 2.5.6 of its App Store Review Guidelines, states, “Apps that browse the web must use the appropriate WebKit framework and WebKit JavaScript.”
WebKit is a browser engine, similar to the Blink engine used for Chromium browsers and the Gecko engine used in Mozilla’s Firefox browser. Each engine implements web standards and APIs that allow the browser to render web pages, but they have differences in terms of performance, security, and supported features.
Apple’s restriction has been a sore spot for web developers since its inception, because it limits the amount of competitive differentiation between browsers on iOS devices and allows Progressive Web Apps (PWAs, which Apple calls Home Screen web apps) access only to the web APIs supported in WebKit.
Presently, browsers such as Brave, Chrome, Edge, Firefox, Opera, and Vivaldi have substantially similar capabilities to Apple’s Safari browser on iOS, because they all run the WebKit engine under the hood. While alternate browser engines may have other capabilities, iOS browser vendors can’t use them.
As a result, browsers on iOS lack support for features like easy home screen installation that would make PWAs more competitive with native iOS apps, a market segment that Apple controls and monetizes. Apple’s App Store ecosystem generated nearly $1.3 trillion [PDF] in billings and sales globally in 2024, so the company has an incentive to ensure that native iOS apps perform better than PWAs.
Apple last year planned to drop support for PWAs until objections by developers and web lobbying group Open Web Advocacy (OWA) prompted the iBiz to reconsider.
Regulators in the European Union and the United Kingdom separately have signaled that they expect Apple to allow non-WebKit browser engines. And Apple made that technically possible last year in iOS 17.4.
While Google and Mozilla began preparing for that possibility at least since 2022, neither has actually attempted to distribute their browser in Europe with the Blink or Gecko engines because Apple’s requirements remain onerous.
To address this, the UK’s Competition and Markets Authority (CMA) in July proposed designating Apple and Google with “strategic market status,” which is the equivalent to Europe’s “gatekeeper” designation under its Digital Markets Act (DMA). We expect a decision in October.
But in Japan, according to OWA, regulators have anticipated Apple’s reluctant compliance. The group notes that Japan’s guidelines explicitly prohibit measures that would hinder the adoption of third-party browser engines.
That means, OWA says, that Apple must not only end its outright ban on non-WebKit engines but must also avoid practices that make implementing third-party engines impractical or financially burdensome.
“This is directly relevant to Apple’s current iOS behavior, even under the EU’s Digital Markets Act, where technical and procedural restrictions continue to block meaningful competition,” the group said in a blog post. “Japan’s guidance is clearly designed to avoid similar outcomes.”
Japan’s Mobile Software Competition Act is expected to come into force in December.
Apple did not respond to a request for comment. ®