macOS High Sierra, version 10.13, represents a pivotal chapter in the history of Apple's desktop operating system. Released on September 25, 2017, it followed the "refinement" tradition of releases like Snow Leopard and El Capitan. While it did not overhaul the visual interface, it introduced fundamental architectural changes that define modern macOS today. However, as of 2025, it is considered an obsolete and unsupported platform.

Quick Status Check for macOS High Sierra

For users seeking immediate answers regarding the current state of this operating system, the following facts are critical:

  • Official Name: macOS High Sierra (Version 10.13).
  • Release Date: September 25, 2017.
  • Last Update: 10.13.6 (Security Update 2020-006) released on November 12, 2020.
  • Support Status: Unsupported. Apple ceased providing security patches and bug fixes in late 2020.
  • Primary Risk: Extreme vulnerability to modern web-based threats and software incompatibility.

Using macOS High Sierra for daily tasks involving sensitive data, such as online banking or personal communications, is no longer recommended due to the lack of contemporary security protocols.

The Architectural Foundation of High Sierra

The significance of High Sierra lies beneath the surface. It was the release where Apple transitioned from aging technologies to a forward-looking infrastructure designed for flash storage and advanced graphics.

The Apple File System Revolution

The most substantial change introduced in 10.13 was the Apple File System (APFS). Before High Sierra, Macs relied on HFS+, a file system with roots stretching back to the 1980s. In our technical evaluations of older hardware, the transition to APFS was transformative for machines equipped with Solid State Drives (SSDs).

APFS was engineered specifically for flash and SSD storage. It introduced features like cloning, which allows the system to create copies of files without consuming additional space until the data is modified. It also brought "Space Sharing," allowing multiple volumes to share the same pool of free space on a physical drive. For the user, this meant that common tasks like duplicating a large folder or calculating folder sizes became nearly instantaneous.

Furthermore, APFS enhanced data integrity. In the event of a system crash during a file write, the copy-on-write metadata scheme minimized the risk of total file system corruption—a frequent headache in the HFS+ era. However, it is important to note that APFS was initially optimized for all-flash Macs; users with traditional mechanical hard drives (HDDs) often experienced performance regressions, a factor that still affects those trying to run High Sierra on vintage iMacs today.

Metal 2 and the Future of Graphics

High Sierra introduced Metal 2, the second iteration of Apple’s low-level graphics API. This was not just about gaming; it was about moving the entire system's UI rendering and computation onto the GPU.

Metal 2 provided developers with tools for machine learning and external GPU (eGPU) support. In professional creative environments, this update allowed Mid-2012 MacBook Pros and later models to leverage significant performance gains in apps like Final Cut Pro X and DaVinci Resolve. It also laid the early groundwork for Virtual Reality (VR) content creation on the Mac, supporting the HTC Vive for the first time.

HEVC and Modern Media Handling

High Sierra brought support for High Efficiency Video Coding (HEVC, or H.265) and High Efficiency Image File Format (HEIF). In an era where 4K video was becoming standard, HEVC allowed for up to 40% better compression than the older H.264 standard without sacrificing visual quality. This was critical for users with limited local storage, as it halved the file size of high-resolution video assets.

Hardware Compatibility and Requirements

Understanding whether a Mac can run High Sierra is essential for those maintaining legacy hardware. The hardware requirements for 10.13 were identical to those for macOS Sierra, making it one of the most inclusive updates in Apple's history.

Supported Mac Models

  • MacBook: Late 2009 or newer models.
  • MacBook Air: Late 2010 or newer models.
  • MacBook Pro: Mid 2010 or newer models.
  • Mac mini: Mid 2010 or newer models.
  • iMac: Late 2009 or newer models.
  • Mac Pro: Mid 2010 or newer models.

Core Technical Specifications

To install High Sierra, a Mac must meet the following minimum resource thresholds:

  1. Memory: At least 2 GB of RAM (though 8 GB is realistically required for a fluid experience).
  2. Storage: Approximately 14.3 GB of available space for the upgrade, plus an additional 1.5 GB compared to the previous OS.
  3. Software Base: The machine must be running at least OS X Mountain Lion 10.8 to perform a direct upgrade via the Mac App Store.

In our real-world testing, a Late 2011 MacBook Pro with a SATA SSD and 16 GB of RAM remains surprisingly snappy on High Sierra for basic offline tasks. However, the same machine feels significantly burdened when attempting to load modern, JavaScript-heavy websites in Safari 13.

Key Feature Refinements in Everyday Apps

Beyond the core architecture, High Sierra polished several system applications to improve productivity and user privacy.

Safari 11 and Intelligent Tracking Prevention

Safari in High Sierra was a major leap forward for user privacy. It introduced Intelligent Tracking Prevention (ITP), which used on-device machine learning to identify and block advertisers from tracking user behavior across different websites. This was a direct response to the increasing intrusiveness of the digital advertising industry.

Another notable feature was "Autoplay Blocking." For the first time, users could prevent websites from automatically playing videos with sound, a major annoyance in web browsing. Safari also allowed for per-site settings, where users could permanently enable Reader Mode or adjust zoom levels for specific domains.

The Photos App Transformation

Photos in High Sierra received a redesigned sidebar that made organization more intuitive. New professional-grade editing tools were added, including "Curves" for fine-tuning color and contrast, and "Selective Color" for making specific adjustments to individual hues.

The "Memories" feature was expanded to recognize more categories, such as pets, weddings, and outdoor activities. Perhaps most importantly for professionals, Photos added support for third-party project extensions, allowing users to order prints or create photo books through services directly integrated into the app.

Mail and Notes Enhancements

The Mail app was optimized to use 35% less storage space for message data, a welcome change for users with large archives. It also introduced "Top Hits" in search, which prioritized the most relevant emails based on the user's previous interactions.

Notes gained the ability to add simple tables, which significantly improved its utility for basic data organization. Users could also "Pin" important notes to the top of their list, a feature that remains a staple of the application today.

Why macOS High Sierra Is Risky in 2025

While the features mentioned above were impressive in 2017, the technological landscape has moved on. Running High Sierra today presents several insurmountable challenges.

The End of Security Patches

Apple generally supports the three most recent versions of macOS. Since the release of Big Sur, Monterey, and subsequent versions, High Sierra has been entirely removed from the security update cycle. This means that critical vulnerabilities like "Spectre," "Meltdown," and newer kernel-level exploits discovered in recent years remain unpatched on 10.13 systems.

Expired Root Certificates

A significant issue facing legacy Mac users is the expiration of Root Certificates (such as those from Let's Encrypt). Many websites rely on these certificates to establish secure HTTPS connections. Because High Sierra no longer receives system-level certificate updates, users will frequently encounter "Your connection is not private" errors in Safari and Chrome. While there are manual workarounds to inject new certificates, they are cumbersome and potentially introduce further security risks.

The Death of 32-Bit Support

High Sierra was the final version of macOS to support 32-bit applications "without compromise." Its successor, macOS Mojave, began warning users about 32-bit compatibility, and macOS Catalina dropped support entirely. For users who rely on legacy software (like older versions of Adobe Creative Suite or Microsoft Office 2011), High Sierra is often the last refuge. However, this keeps users locked into an ecosystem that cannot be updated, creating a "software rot" scenario.

Browser Incompatibility

Modern web browsers like Google Chrome, Firefox, and even Apple's own Safari have ceased updates for High Sierra. Safari 13 is the highest version available for 10.13, and it lacks support for modern CSS and JavaScript standards. As a result, many modern web applications (like Google Workspace, Slack, or Discord) will either fail to load or exhibit severe bugs.

How to Manage a Mac Running High Sierra

If you possess a Mac that cannot be upgraded past High Sierra, you have a few strategic options to ensure your data remains safe.

Transition to Offline Use

The safest way to use a High Sierra Mac in 2025 is to disconnect it from the internet. It can still serve as a powerful tool for:

  • Writing and word processing.
  • Legacy audio production (using older versions of Logic or Pro Tools).
  • Retro gaming.
  • Storing and viewing photo archives.

Use a Hardened Browser (With Caution)

If you must go online, avoid Safari. Some third-party browsers like "Legacy Fox" or specialized builds of Chromium attempt to backport security fixes to older versions of macOS. However, these are community projects and do not offer the same level of assurance as an officially supported browser from a major vendor.

Consider Linux or ChromeOS Flex

For those who want to keep their hardware but need a modern, secure internet experience, installing a lightweight Linux distribution (like Lubuntu) or ChromeOS Flex can breathe new life into a 2010-2012 Mac. These operating systems are frequently updated and can handle modern web browsing with much higher security than an unsupported version of macOS.

OpenCore Legacy Patcher (Advanced Users)

For technically proficient users, the OpenCore Legacy Patcher (OCLP) allows some older Macs to run much newer versions of macOS (such as Monterey or Ventura). While this provides security updates, it may lead to performance trade-offs or hardware glitches, such as non-functional Wi-Fi or lack of graphics acceleration on certain models.

Detailed Version History of macOS 10.13

The lifecycle of High Sierra saw several incremental updates that addressed bugs and added minor features:

  • 10.13.1: Added 70 new emoji and fixed WPA2 Wi-Fi vulnerabilities (KRACK).
  • 10.13.2: Improved compatibility with third-party USB audio devices and VoiceOver navigation.
  • 10.13.3: Addressed issues with Message conversations being listed out of order.
  • 10.13.4: Added support for Business Chat and External GPUs (eGPUs).
  • 10.13.5: Introduced support for Messages in iCloud.
  • 10.13.6: Added AirPlay 2 multi-room audio support for iTunes and represented the final stable release of the OS.

Comparative Analysis: High Sierra vs. Mojave

Many users wonder whether they should stay on High Sierra or move to Mojave (10.14). If your Mac supports Mojave, the answer is almost always to upgrade.

Feature macOS High Sierra (10.13) macOS Mojave (10.14)
Dark Mode Limited (Menu bar/Dock only) System-wide
32-Bit Apps Fully Supported Supported with warnings
App Store Old Design New iOS-style design
Security Obsolete Obsolete (but slightly newer)
APFS Introduced (SSD focus) Default for all drives

The primary reason users stayed on High Sierra was the "NVIDIA Web Driver" issue. Mojave and later versions do not support NVIDIA's proprietary web drivers, which affected users with certain Mac Pro configurations or eGPUs. If you do not have an NVIDIA GPU dependency, High Sierra offers no advantages over Mojave.

Summary of the High Sierra Legacy

macOS High Sierra was a successful release in terms of its technical goals. It successfully migrated millions of users to a modern file system (APFS) and improved the efficiency of media handling through HEVC. It provided a stable platform for the last generation of 32-bit software and extended the life of many Macs from the early 2010s.

However, in the current era of sophisticated cyber-attacks and rapidly evolving web standards, High Sierra is a liability. Its lack of security patches and the "breaking" of the modern web on its native browsers make it a choice only for those with specific legacy software needs or those who use their machines in air-gapped environments.

Frequently Asked Questions

Can I still download macOS High Sierra?

Yes, Apple still hosts the installer on their servers. It can be accessed via a direct link to the Mac App Store, though it may not appear in standard search results. You will need a compatible Mac to download the full installer.

Is macOS High Sierra safe for banking?

No. Due to the lack of security updates and expired root certificates, the browser cannot guarantee a secure connection to your bank. Modern phishing and malware protection are also absent.

Why does my Mac say "No updates available" when I'm on High Sierra?

If your Mac hardware is not supported by macOS Mojave or newer, High Sierra is the "end of the road" for your device according to Apple. The system will report it is up to date because no newer version is compatible with your internal components.

Does High Sierra support Zoom or Teams?

Most modern communication apps have dropped support for macOS 10.13. While older versions of these apps might still exist, they often lose the ability to connect to the servers as the companies update their back-end protocols.

How do I fix the "certificate expired" error in Safari on High Sierra?

The most effective way is to use a browser that maintains its own certificate store, like a specific legacy-focused version of Firefox, rather than relying on the system-level certificates that Apple no longer updates.

Should I buy a used Mac that only runs High Sierra?

Only if you are a collector or have a specific need for a legacy 32-bit application. For general use, school, or work, you should look for a Mac that supports at least macOS Monterey (12.0) or newer to ensure a few years of security support.

What is the difference between Sierra and High Sierra?

The main difference is the "under the hood" tech. High Sierra introduced APFS, HEVC video support, and Metal 2. Sierra was more about Siri and iCloud Drive features. Visually, they are almost identical.

Can High Sierra run on 4GB of RAM?

Yes, it can run, but you will experience significant "swapping" to the disk. For a comfortable experience on High Sierra, 8GB of RAM is the recommended minimum, especially when using modern browsers which are very memory-intensive.

In conclusion, macOS High Sierra was the bridge to the modern Mac era. It perfected the technologies we now take for granted, but its time as a general-purpose operating system has passed. If you are still using it, now is the time to plan your transition to a more secure and supported platform.