How mobile browsers work
Accessing websites from your mobile relies on the following vertical stack of functions:
Mobile operating system: pre-installed software on smartphones and tablets enables them to run programs and applications. A mobile operating system loads when smartphone is turned on, displays a home screen with icons for selecting and accessing a range of apps and behind the screen, facilities critical functions such as a keyboard, managing memory allocated to programs and keeping time. Most of the mobile world is split into the largely mutually exclusive domains of Apple’s iOS and Google’s Android.
Browser engine: the core software responsible for processing HTML, CSS and JavaScript code and rendering websites into the visual format that users see on their smartphones. The browser engine needs to be compatible with the operating system. The leading browser engines are Apple’s Webkit, which Apple specifies as the only browser engine that can be used on iOS, Google’s Blink and Gecko.
Browsers: the user interface enabling to interact with content on the web, such as opening a website by typing in its URL or clicking on a hyperlink (which embeds the URL). The browser stores web favourites and browsing history, remembers passwords and payment details and can provide additional privacy and security features. Apple’s Safari browser accounts for 88% of mobile browsers on iOS and Google’s browser Chrome accounts for 77% of mobile browsers on Android devices and together the two browsers account for 90% of the whole browser market. Smaller competitors include Mozilla (Firefox), Microsoft (Edge), Samsung (Samsung Internet), Opera (Opera) and Brave (Brave). A browser is built on top of a browser engine. This means that, for example, Google’s Blink can be used by a third party to build a browser which competes against Google’s Chrome. A browser is usually pre-installed on a smartphone: Safari in the case of iOS, reflecting Apple’s vertically integrated business model and Chrome in the case of many Android devices under arrangements in which Google pays manufacturers.
Search engines: software that allows people to find information on the web using keywords and phrases. The main search engines are Google, Bing, Yahoo Search and DuckDuckGo. While browsers need to be installed on a smartphone, search engines are internet-based and accessible from a smartphone through the browser: for example Google search can be accessed through any browser, not just Google Chrome. However, browsers usually have a default search engine URL as their launch page. Apple has agreed with Google, that Google is the default search engine for Safari, for which Apple receives a share of Google’s search revenues amounting to over US$20 billion annually.
Web sites: developers must ensure the websites they create are compatible with different mobile browsers, reached by the user either directly through the browser by entering the URL or through a search engine using the browser in the background.
How competition works
While your new smartphone straight-out-of-the-box will let you browse and search the internet, there is a complex chain of competition down the vertical stack outlined above:
Handset manufacturers compete for users to buy their products on the functionality delivered by the operating system and the apps (including browsers) which depend on that system.
Browser engine vendors compete to be chosen by browser vendors as the base to build their product on. Competition between browser engines is based on ease in turning the engine into a browser, by ensuring strong compatibility with online content and by implementing advanced features enabling browsers to provide a better user-facing experience. Browser engines are typically made available on an open-source basis.
Browser and browser engine vendors compete to be prioritised for web developers to build websites that are compatible with a particular browser and browser engine. As web developers need to build different versions of their websites for each browser, the more users a browser has the more willing a developer is to build a website compatible with that browser.
Browser vendors compete for handset vendors to pre-install their browser or for users to install their browsers to use in preference to the pre-installed browser. Browser vendors compete on under features, privacy and security settings, battery life and performance in loading web sites. Browsers are not monetised directly, with users typically being offered browsers free of charge. However, browser vendors are still able to generate revenue through their browser via search agreements (where search advertising revenue is shared by a search service provider with the browser vendor).
The problem is that, as the CMA provisional decision points out, this chain of competition hits two brick walls of inertia (our words not theirs):
Web developers face costs and time to ensure the websites they create are compatible with different mobile browsers and browser engines. Web developers are therefore most likely to design content to run on the mobile browsers with the most users which the CMA report observes, creates ‘network effects’. Most developers surveyed by the CMA design for 2-4 browsers, mostly Safari, Chrome, Mozilla or Edge. Yet developers also reported that ensuring compatibility across browsers was a relatively small part of their work, estimating that it typically took 5-10% of their time.
Many consumers are not aware of (or even care much about) the particular browser they are using at any given time, that they have a choice of browsers, or why to choose one browser over another. Only 7% of surveyed consumers identified the web browser available on a device as an important factor in buying the device and only 16% of UK users downloaded a different mobile browser from the one which came pre-installed with their phone.
The CMA provisional decision essentially finds the technical, operational and commercial practices of Apple and, to a less extent, Google create, reinforce and exploit the inertia to limit competition in mobile browsers and browser engines.
Apple
The CMA provisional decision identifies the following practices as reinforcing the dominance of Apple’s Safari on iOS:
Through its control of the iOS operating system, Apple specifies that third party mobile browsers installed on its handsets must use Apple’s own underlying browser engine WebKit, which determines what competing mobile browsers can do on iOS. This constrains the scope for product differentiation between browsers on iOS (including the ability to develop ‘superior’ browsers to Safari) including to make available in the iOS version of a browser functionality which is available on Android: for example Microsoft says it is prevented from providing additional security features to protect from malicious attacks online which are available in its desktop browser products. Opera said it was not able to fully implement Web3 protocols (based on blockchain technologies) on the iOS version of its mobile browser.
Although Webkit is open source and Apple says it provides equivalent access between Safari and other browsers, there was evidence of preferential access for Safari, at least in the past. Safari was able to implement full screen video almost four years before Apple allowed other browsers access to the functionality required to do so.
Increasingly, apps allow users to access web content through an inbuilt browser rather than toggle to or be directed to the standalone browser (called in-app browsing (IAB)). While the CMA provisional decision concluded that IAB was not (yet) a close substitute for a standalone browser (for example only displaying a couple of web pages on each browsing activity), third party IAB on iOS provided some out of market constraint on Apple’s Safari. However, the CMA provisional decision found that Apple limits the technology available to link to web content from within an app.
While pre-installation of Safari on iOS devices clearly benefits users, Apple’s ‘choice architecture’ limits the willingness of users to install and use a competing browser post-purchase:
There is no central point in the device settings menu where users can change the default browser and no way of searching on iOS to find which page to navigate to in order to change the default browser.
If a user downloads an alternative browser to Safari and sets that browser as their default browser, the third-party browser will not automatically appear on the Default Home Screen, while Safari will still be positioned in the application dock. The user must take active steps to customise the application dock to have the new browser displayed, which requires more toggling through pages to work out how to do.
Safari cannot be uninstalled from iOS devices (while other mobile browses can be).
Apple argued its tight vertical control is driven by its business model of offering a high quality, secure, ‘whole of environment’ user experience on iOS. While the CMA provisional decision acknowledged WebKit’s integration between device hardware and software provides some security and privacy benefits, these could be achieved by means that are less restrictive of competition: for example Apple imposing minimum security standards on mobile browsers using browser engines other than WebKit. More fundamentally, CMA provisional decision also rebutted ‘Apple knows best’ attitude user privacy and safety on the basis that if iOS was more open to competing browser engines and browsers others could develop more enhanced privacy and security measures than Apple.
While Google’s Blink browser engine is the main browser engine on Android, with a share of at least 95%, the CMA provisional decision found there was no evidence of Google using its position as an operating system and mobile browser engine provider to favour Chrome.
Commercial arrangements between Google and Android handset manufacturers ensure Chrome is pre-installed on most Android devices. However, manufacturers are free to pre-install other browsers: for example Samsung devices have both Chrome a Samsung browser pre-installed, although most Samsung users use Chrome for browsing.
The CMA provisional decision found, by comparison with Apple:
Friction in the user journey for changing the default browser settings away from Chrome does not restrict users from switching between mobile browsers.
While Chrome like Safari cannot be uninstalled, it can be disabled, and its icon can be fairly readily replaced with the new default browser on the default home screen.
However, the CMA provisional decision also found that Google’s use of op-up prompts from its first party apps, such as Google Maps, to encourage users to reset Chrome as their default browser “makes it harder for browser vendors to retain newly switched users and therefore, compete with Google, limiting competition between mobile browsers on Android”.
Apple and Google
Apple and Google have struck an agreement in which Google shares with Apple a significant share of the Google search advertising revenue earned from traffic both on Safari (for which Apples sets Google as the default search engine) and Chrome on iOS (about 16% of iOS users use Chrome rather than Safari, which makes Chrome the largest third-party browser on iOS). The CMA provisional decision says this agreement means:
The extent of this revenue-sharing is so large that the revenue share they earn from their competitor’s product is lower but similarly significant to the revenue share they earn from their own, so that the incremental revenue from winning customers and therefore the financial incentive to compete, is limited.
If Google fought harder to win over more users of its iOS version of Chrome, Google would not be much further ahead after it pays the share of Chrome-based Google search revenue to Apple than where users stay with Safari and Google has to pay Apple the share of Safari-based Google search revenue.
Remedies
The independent expert group recommended that the CMA move quickly to consider designating both Apple and Google as having strategic market status (SMS) under the UK’s new Digital Markets, Competition and Consumers Act 2024, which gives the CMA broad powers to impose, monitor and adjust conduct rules and pro-competition interventions on SMS providers.
The independent expert group left it to the CMA to decide on the appropriate measures of Apple and Google were designated as SMS. However, they discussed at length the following four potential remedies which they did not propose to take forward:
Requiring Apple to allow use of alternative browser engines on iOS.
Mandating Apple to provide equivalent WebKit access for all WebKit-based browsers on iOS.
Requiring Apple to allow developers on iOS to bundle their own engine to implement in-app browsing in their native apps.
Prohibition of revenue-sharing under the Apple-Google agreement for iOS Chrome.
Rules requiring changes to Apple and Google choice architecture for their pre-installed browsers.
The independent expert group essentially decided that these remedies would require a highly detailed technical specification which would be difficult for outsiders to develop, would be susceptible to circumvention because of the technical detailed involved, would be difficult to monitor because of the large information asymmetries between Apple/Google and the outside monitors, would need to be regularly reviewed and restruck because of the rapid changes in technology, and would need a highly expert independent dispute resolution process.
There was also a concern that, given the interconnectedness of the technology and cross relationship of services offered on a single digital platform, there would be distortions caused in neighboring markets, such as search.
While the independent expert group was clear on what it was (provisionally) ruling out, it’s a bit of a hospital pass to the CMA itself to decide what conduct rules to apply if Apple and Google are designated as having SMS.
Read more: Provisional decision report
Peter Waters
Consultant
