Safari
By Apple
Safari is Apple's default web browser for macOS, iOS, and iPadOS, built on the WebKit rendering engine that Apple also develops. It handles loading, rendering, and interacting with websites across Apple's device ecosystem, with a strong…
Definition
Safari is Apple's default web browser for macOS, iOS, and iPadOS, built on the WebKit rendering engine that Apple also develops. It handles loading, rendering, and interacting with websites across Apple's device ecosystem, with a strong emphasis on battery efficiency and integration with Apple's privacy and platform features. Safari has shipped as the preinstalled default browser on every Mac and iOS device since its introduction in the early 2000s.
Overview
Safari was introduced by Apple in the early 2000s to replace third-party browsers as the default on Mac systems, and Apple built it on WebKit, an engine it derived from the open-source KHTML project. Over time Safari became the exclusive engine allowed for third-party browsers on iOS, since Apple's App Store rules require any browser on iOS to use WebKit under the hood, regardless of what engine it uses elsewhere. Mechanically, Safari uses WebKit to parse and render HTML and CSS and the JavaScriptCore engine to execute page scripts. Apple tunes Safari's process and power management specifically for its own hardware, aiming to minimize battery drain and memory pressure on laptops and mobile devices, an area where Apple has often highlighted Safari's efficiency compared to Chromium-based alternatives running the same hardware. Safari also includes Intelligent Tracking Prevention, which uses on-device machine learning to classify and limit cross-site trackers without sending browsing data off the device. Within the browser landscape, Safari is one of only two major browser engines, alongside Firefox's Gecko, that remains independent of the Chromium/Blink codebase, which keeps some competitive pressure on how web standards evolve. It differs sharply from Chrome and Firefox in platform availability, since Safari is only available on Apple's own operating systems and, historically, an unsupported Windows version that Apple discontinued. In practice, Safari is the default and most-used browser on iPhones and iPads because Apple requires all iOS browsers to use WebKit, making Safari's rendering behavior the practical baseline that web developers must test against for the entire iOS user base regardless of which browser app a person has installed. On macOS, Safari is valued for battery life and native integration with iCloud, Handoff, and Apple's password and payment autofill systems. Safari's trade-offs mirror WebKit's own limitations: because it is the sole engine permitted on iOS, any web platform feature Safari has not yet implemented is effectively unavailable to the entire iOS browser market, which has occasionally put Safari at the center of disputes over slow adoption of certain APIs favored by competing browser vendors. Developers building progressive web apps in particular have flagged gaps between what Safari supports and what Blink-based browsers support, requiring extra testing and fallback code specifically for the Apple ecosystem. Apple has gradually narrowed some of these gaps in successive Safari and WebKit releases, but the pace and scope of that work remains a frequent point of comparison against Chromium's faster feature rollout.
Key Features
- Built on Apple's own WebKit rendering engine
- Uses the JavaScriptCore engine for script execution
- Includes on-device Intelligent Tracking Prevention
- Optimized for battery efficiency on Apple hardware
- Integrates with iCloud Keychain for password and payment autofill
- Supports Handoff to continue browsing across Apple devices
- Required as the underlying engine for all browsers on iOS
- Provides a Reader mode for distraction-free article viewing