Slo vs White Noise: Sound Machine Apps Compared (2026)

Feature	Slo	White Noise
Brown Noise	✓	✓
White Noise	✓	✓
Sound Mixer	✓	✓
Sleep Timer	✓	✓
Nature Sounds	✓	✓
Sound Library	70+	50+
Community Sounds	—	✓
Custom Recording	—	✓
iOS App	✓	✓
Android App	✓	✓
Mac App	✓	✓
Windows App	—	✓
Free Version	✓	Lite (free)
Price	Free / Premium	$0.99 one-time

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Overview

Slo and White Noise (by TMSOFT) are both ambient sound apps designed for sleep and relaxation, but they represent different generations and approaches to the category. White Noise is one of the longest-running noise apps, having been available for over 10 years with a one-time purchase model and a community-driven sound marketplace. Slo is a newer entry focused on sound mixing with a curated library and modern design. This comparison covers the features, platforms, and pricing of both apps.

What Slo Offers

Slo is an ambient sound app focused on sleep, focus, and relaxation. The app provides 70+ sounds including brown noise, white noise, pink noise, nature recordings, and atmospheric audio. The sound mixer allows users to layer multiple sounds at adjustable volumes to create custom soundscapes.

Slo is available on iOS, Android, and macOS. The app includes a sleep timer and features a minimal, modern interface designed for quick access to sounds. A free tier provides access to select sounds, with a premium subscription unlocking the full library.

The app provides a curated library where all sounds are selected and produced by the development team. Slo does not include community-uploaded content or custom recording features.

What White Noise Offers

White Noise by TMSOFT is one of the original noise and sleep sound apps, having launched over a decade ago. The app includes 50+ built-in sounds covering noise types, nature, mechanical sounds, and urban environments. Like Slo, it includes a mixer for combining sounds.

What distinguishes White Noise is its community sound marketplace, where users can upload, share, and download custom recordings. This has resulted in a large library of user-created content beyond the built-in sounds. The app also includes a custom recording feature that allows users to record their own sounds for playback and mixing.

White Noise is available across a wide range of platforms: iOS, Android, macOS, and Windows. This broad platform support makes it one of the most widely available noise apps. The app also supports features like alarm clocks, favorite mixes, and audio playback customization.

The app uses a one-time purchase model at $0.99, with a free “Lite” version available that includes ads and a reduced feature set. There is no subscription required for the full app.

Key Differences

Pricing Model

White Noise uses a one-time purchase model at $0.99 for the full version, making it one of the most affordable paid noise apps available. Slo offers a free tier with select sounds and a subscription model for premium access. Users who prefer to pay once without recurring charges would find that in White Noise. Users who prefer to try sounds before committing would find Slo’s free tier useful.

Community Content

White Noise includes a marketplace where users upload and share their own recordings. This community-driven approach has created a large supplementary library beyond the built-in sounds. Users can find niche recordings (specific fan types, specific locations, specific environments) uploaded by other users. Slo provides only a curated, developer-produced library without community uploads.

Custom Recording

White Noise allows users to record audio directly in the app and use those recordings in their sound mixes. This means users can capture their own fan, environment, or ambient noise and play it back later. Slo does not include recording functionality.

Design and Interface

Slo uses a modern, minimal interface designed around the mixing experience. White Noise uses a functional interface that has evolved over its 10+ year history, accommodating its large feature set including alarms, favorites, marketplace browsing, and recording tools. The aesthetic approaches reflect their respective eras of development.

Sound Library

Slo provides 70+ curated sounds focused on noise colors and nature. White Noise provides 50+ built-in sounds plus access to community-uploaded content. The total available sound count in White Noise can be significantly higher when including marketplace content, though quality varies with user-submitted recordings.

Platform Coverage

White Noise is available on iOS, Android, macOS, and Windows, making it one of the broadest in platform support. Slo is available on iOS, Android, and macOS. Users who need a Windows app would find that in White Noise but not in Slo.

App Maturity

White Noise has been available for over 10 years and has gone through many iterations. Its feature set reflects a decade of user feedback and platform evolution. Slo is a newer app with a focused feature set and modern design language. Users who value proven reliability and established community would find that in White Noise. Users who prefer a fresh approach with modern design conventions would find that in Slo.

Which App Is Right for You?

If you are looking for an affordable, feature-rich noise app with community content, custom recording, and broad platform support including Windows, White Noise provides exceptional value at $0.99 with no subscription. The community marketplace adds virtually unlimited sound variety, and the app’s longevity demonstrates sustained support.

If you are looking for a modern sound mixing app with a curated library, clean interface, and a free tier to explore before committing, Slo provides a focused experience designed around creating custom soundscapes. The minimal design and curated library mean less time browsing and more time listening. To understand why white noise helps sleep, check our dedicated guide.

Both apps include sound mixing, sleep timers, and are available on iOS, Android, and macOS. The choice often comes down to pricing preference (one-time vs subscription), interest in community content, and design aesthetic preferences.

Information based on publicly available data as of April 2026. Visit the official White Noise (TMSOFT) and Slo app store listings for the most current details.

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