Browser Mining on Safari: Current Limitations and Workarounds

Safari's WebAssembly thread limits and aggressive power throttling cut browser mining hashrates. Learn the numbers, workarounds, and how to optimize your Earnify setup.

Safari remains a significant share of desktop traffic — roughly 18–20% globally, and higher in markets like the US and Australia. Yet when it comes to browser-based cryptocurrency mining, Safari consistently underperforms Chrome, Firefox, and Edge. For publishers using Earnify's zero-server mining solution, understanding these limitations is critical for accurate revenue projections and user experience.

In this post, we break down exactly why Safari struggles with browser mining, share real benchmark data, and provide actionable workarounds for both publishers and users. According to Earnify's 2026 compatibility report, Safari delivers only 30–60% of Chrome's hashrate on MinotaurX, depending on server headers and user settings. Let's dive in.

Why Safari is a Problem for Browser Mining

Safari's engine, WebKit, takes a deliberately conservative approach to resource-heavy web technologies. That approach has benefits — longer battery life, fewer security vulnerabilities, and a smoother browsing experience — but it directly impacts mining performance. Two major factors stand out: the WebAssembly thread gap and aggressive power throttling.

The WebAssembly Thread Gap

Modern CPU-mining algorithms like MinotaurX rely on WebAssembly (WASM) for near-native execution speed. In Chrome and Firefox, WebAssembly threads and SIMD (Single Instruction, Multiple Data) instructions are fully supported. Safari, however, has lagged behind. As of Safari 17, WebAssembly SIMD is available, but WebAssembly threads require SharedArrayBuffer, which Safari disables by default for security reasons (Spectre mitigations).

Without SharedArrayBuffer, a mining script cannot safely share memory between Web Workers. Earnify's zero-server architecture normally spawns n-1 workers (one for the UI thread). In Safari without cross-origin isolation, all hashing must run on a single thread, collapsing parallel performance. Even with cross-origin isolation headers enabled, Safari's thread scheduler is less efficient than Chrome's, resulting in a persistent ~35% performance deficit.

According to Earnify's 2026 hashrate benchmarks, a desktop visitor on MinotaurX averages 1,870 H/s in Chrome, but only 1,150 H/s in Safari with cross-origin isolation enabled — and a mere 480 H/s without it.

Aggressive Power Throttling

Safari is designed to maximize battery life on MacBooks and iPads. When a tab is not visible, Safari aggressively throttles JavaScript timers and Web Workers. Background tabs can be frozen entirely after a few minutes, and macOS Low Power Mode further reduces CPU frequency. This means mining only works when the user is actively viewing the page, and even then, sustained load may be capped.

For publishers, this translates to smaller effective session times and less total hashpower from Safari visitors. Earnify's analytics show that the average Safari mining session lasts 40% shorter than Chrome sessions due to automatic tab suspension.

How Safari Limits Hashrate: Benchmarks and Numbers

To quantify the gap, Earnify ran controlled benchmarks on a 2023 MacBook Pro (M2 Pro, 10-core CPU), using the same page, same mining pool, and same MinotaurX algorithm across four browsers. The results are sobering.

The impact on revenue is just as stark. Assuming a DOGE payout of $0.08 per 1,000 H/s per day and a visitor mining for 10 active minutes, a Chrome visitor earns approximately $0.025, while a Safari visitor without cross-origin isolation earns $0.0064 — a 74% reduction. Multiply that across thousands of Safari visitors, and the gap becomes a serious revenue leak.

Workarounds for Publishers and Users

Despite these limitations, Safari users can still contribute meaningful hashpower. The key is to implement server-side and client-side adjustments that squeeze the most out of WebKit's constrained environment.

Optimizing Your Site for Safari Miners

The single most effective publisher-side fix is enabling cross-origin isolation. This requires sending two HTTP headers on all responses:

// Apache .htaccess
Header set Cross-Origin-Opener-Policy "same-origin"
Header set Cross-Origin-Embedder-Policy "require-corp"

For Nginx:

# nginx.conf
add_header Cross-Origin-Opener-Policy "same-origin" always;
add_header Cross-Origin-Embedder-Policy "require-corp" always;

Once these headers are present, SharedArrayBuffer becomes available in Safari, allowing Earnify's Web Workers to run in parallel. According to Earnify's internal tests, this single change lifts Safari hashrate from 480 H/s to 1,150 H/s — a 140% improvement.

Additionally, publishers should use the visibilitychange event to pause mining when the tab loses focus. Safari will throttle anyway, but gracefully suspending workers prevents wasted CPU cycles and keeps users from noticing performance drops.

User-Side Adjustments

Users on Safari can also take steps to improve their mining contribution:

• Disable Low Power Mode in System Settings → Battery. This removes aggressive CPU frequency scaling.
• Keep the mining tab active and visible. Avoid switching to other tabs or minimizing the window; Safari throttles hidden tabs almost immediately.
• Use Safari Technology Preview. Apple's experimental browser often includes newer WebAssembly features before the stable release.
• Consider switching to Chrome or Firefox for mining sessions if they want to maximize their contribution. Earnify's benchmarks show Chrome delivers 63% higher hashrate than Safari under identical conditions.

Implementing a Safari-Aware Mining Strategy with Earnify

Earnify's zero-server architecture means there is no backend to manage, but publishers can still customize the client-side script to adapt to Safari's quirks. The following snippet detects Safari and automatically reduces the worker count to avoid browser freezes:

// Detect Safari (desktop)
const isSafari = /^((?!chrome|android).)*safari/i.test(navigator.userAgent);

// Use fewer workers on Safari; keep at least one for UI
const workerCount = isSafari 
  ? Math.min(2, navigator.hardwareConcurrency - 1) 
  : navigator.hardwareConcurrency - 1;

eanify.start({
  workers: workerCount,
  throttle: 0.2
});

// Pause when tab is hidden (Safari will throttle anyway)
document.addEventListener('visibilitychange', () => {
  if (document.hidden) {
    earnify.pause();
  } else {
    earnify.resume();
  }
});

Earnify charges a flat 10% platform fee, leaving 90% of mining rewards to the publisher. On a busy site with 10,000 daily Safari visitors, even a 74% hashrate reduction still generates meaningful DOGE revenue — but with the cross-origin isolation fix, that same audience can produce nearly 2.4x more. For a deeper dive into maximizing earnings, see our guide on MinotaurX Hashrate Benchmarks Across Devices.

The Future of Safari Mining

Apple has been slowly aligning WebKit with modern WebAssembly standards. Safari 18 (released in 2025) introduced experimental support for WebAssembly threads behind a flag, and the WebKit team has signaled continued investment in SIMD and memory model improvements. However, given Apple's strong emphasis on battery life and privacy, Safari will likely always be more conservative than Chrome or Firefox when it comes to sustained CPU loads.

For publishers, this means treating Safari as a secondary mining audience for the foreseeable future. The good news is that cross-origin isolation and user-agent detection can recover a large portion of lost hashrate. For more on browser mining best practices, read our article on Optimizing Web Workers for CPU Mining and Common Browser Mining Myths Debunked.

FAQs

Does Earnify work on Safari at all?
Yes, but with reduced hashrate. According to Earnify's 2026 benchmarks, Safari delivers between 480 and 1,150 H/s depending on cross-origin isolation, compared to 1,870 H/s in Chrome. It still mines DOGE and other CPU-mineable coins via MinotaurX.

What can I do to improve Safari mining performance on my site?
Enable cross-origin isolation headers (COOP/COEP), use the visibilitychange event to pause/resume mining, and reduce worker count for Safari via user-agent detection. Earnify's script automatically adjusts when headers are present.

Will Safari ever support full-speed browser mining?
WebKit is gradually adding WebAssembly threads and SIMD support, but due to power efficiency and privacy priorities, Safari will likely always be more conservative than Chrome. Publishers should diversify by optimizing for multiple browsers.

Frequently Asked Questions