Apple’s long-standing control over iPhone browser technology is facing a major challenge in Japan. Under recently released guidelines tied to the Smartphone Act, regulators are pushing the company to allow third-party browser engines on iOS, a move that could reshape the mobile web experience for millions of users.
The new rules not only give Apple a clear compliance deadline of December, but also ban “unreasonable technical restrictions” or other tactics that could deter developers from adopting alternatives to Apple’s own WebKit engine.
For years, Apple has mandated that all browsers on iOS whether Safari, Google Chrome, Mozilla Firefox, or others must use WebKit, its proprietary browser engine.
This rule has effectively:
- Prevented browsers from using their native engines like Google’s Blink or Mozilla’s Gecko.
- Limited web performance and feature parity compared to desktop or Android versions.
- Given Apple tight control over security, privacy, and app store compliance.
Critics argue this stifles innovation and slows down the adoption of modern web technologies on iOS.
Japan’s Smartphone Act: The Game-Changer
The Smartphone Act, designed to promote fair competition in the mobile ecosystem, has now zeroed in on browser engine restrictions. According to translated guidelines from the advocacy group Open Web Advocacy (OWA), Japan’s regulators are making it clear that Apple must not only allow alternative engines but also avoid creating new barriers to their adoption.
The guidelines explicitly prohibit:
- Unreasonable technical restrictions on app providers when adopting alternative browser engines.
- Excessive financial burdens for developers choosing non-WebKit solutions.
- User steering tactics that push people away from apps using third-party engines.
This means Apple can’t comply in name only, it must genuinely enable competition.
Malicious Compliance Concerns: Lessons from the EU
The EU’s Digital Markets Act (DMA) theoretically already requires Apple to allow competing browser engines. However, developers and advocacy groups say Apple has engaged in “malicious compliance” introducing alternative browser support only in limited ways that are impractical or unattractive for developers.
Examples cited include:
- Complex permission requirements.
- Inconsistent APIs.
- Retained control over system-level integration.
By contrast, Japan’s approach is more prescriptive, explicitly blocking such loopholes.
Why This Matters for iPhone Users
If Japan enforces these rules effectively, iPhone users could soon install browsers that truly compete with Safari, both in speed and functionality.
Potential changes:
- Google Chrome on iOS could finally use its Blink engine, matching the Android and desktop versions in performance and feature set.
- Mozilla Firefox could run on Gecko, enabling support for its unique privacy tools and open web standards.
- Web apps could gain capabilities currently restricted by WebKit, closing the gap between mobile and desktop browsing.
For users, this could mean faster load times, richer web experiences, and more choice in privacy features.
The Japanese guidelines set December 2025 as the compliance deadline. Between now and then:
- Apple may need to update iOS to allow installation of browsers with different engines.
- Developers could begin porting their full-featured browsers to iOS.
- Advocacy groups will likely monitor closely to ensure Apple isn’t using subtle tactics to maintain its advantage.
Whether Apple will resist or cooperate remains unclear. The company has historically defended WebKit restrictions as necessary for security and battery efficiency, but regulators are signaling that competition and developer freedom outweigh those arguments.
Japan’s move could have far-reaching consequences beyond its borders:
- If successful, it might inspire South Korea, Australia, and the U.S. to adopt similar measures.
- Combined with the EU’s ongoing enforcement, this could mark the beginning of the end for WebKit’s dominance on iOS.
- Developers may finally be able to maintain one unified codebase for their browsers across platforms, reducing costs and improving feature parity.
Organizations like Open Web Advocacy have long campaigned for exactly this kind of regulatory intervention. They argue that browser engine diversity is critical for:
- Web innovation: Competing engines drive adoption of new standards.
- Security: Multiple engines reduce the impact of a single vulnerability.
- Consumer choice: Users get to pick browsers based on features, not on which engine Apple allows.
OWA praised Japan’s clarity, noting that explicitly banning technical and financial barriers closes the loopholes that have hampered EU enforcement.
Japan’s December deadline could be a watershed moment in the fight for browser competition on iOS. If regulators hold firm, iPhone users in Japan could become the first in the world to experience true browser choice not just cosmetic alternatives built on WebKit.
For Apple, the challenge will be balancing security and user experience with compliance and openness. For the rest of the world, Japan’s experiment may become a blueprint for breaking down platform gatekeeping in mobile computing.
