Slo vs Calm (2026): Sound Mixer or Wellness Library?

Slo suits you if you want to put your own ambient mix together, with 200+ sounds and 89 of them free, a volume for every layer, a timer from 15 minutes to 24 hours, and 180 sounds free in the browser at slonoise.com. Calm suits you if its 300+ narrated Sleep Stories and its guided meditation library belong in your bedtime routine. Slo is our own app, so read this knowing that.

The short answer: you’re probably working out whether the Calm subscription is still earning its place. If the part you open is the sound, Slo does that one job and keeps your mix, because it remembers the balance of every combination, and the full library costs a monthly or yearly subscription or a single lifetime purchase. If you open Sleep Stories, meditation, music and finished soundscapes, Calm is the wider library and Slo can’t stand in for it.

What this page says about Calm comes from Calm’s official product and support pages, read on July 31, 2026. Our own figures come from the Slo app source, version 3.132, on September 14, 2026. Neither app can guarantee better sleep.

Slo vs Calm at a glance

If you care most about…	Better fit	Why
Combining your own ambient layers	Slo	Stack as many layers as you want, give each one a volume, and the app keeps that balance per combination.
Narrated bedtime content	Calm	Its documented library runs to more than 300 Sleep Stories.
Guided meditation and wellness programs	Calm	That’s the center of what Calm sells.
Testing ambient audio in a browser	Slo	You can play 180 sounds at slonoise.com without an account or an install.
Downloading Sleep Stories for offline listening	Calm	Offline downloads for Sleep Stories are documented on Calm’s own pages.

No app is the right answer for everyone. This page describes what each product does and how it feels to use, and it says nothing about medical effectiveness.

What is the main difference?

With Slo you start from nothing and add sound. The app holds 200+ recorded sounds and 89 of them stay free, including 22 noise-color recordings across seven colors, 5 of them brown. Add as many layers as you want, set a volume for each, and the app stores that balance for the combination, so the mix comes back the same tomorrow. Saved mixes travel as files, so one can be imported on another device. The sleep timer runs from 15 minutes to 24 hours and fades the sound out over up to 2 minutes, so the quiet doesn’t land all at once. On iPhone and Android it plays as a background service, which is how it keeps going with the screen locked all night. Each sound downloads on first play and stays on the device, so in the app a saved mix plays with the phone in airplane mode. Paying for the full library means a monthly subscription, a yearly one, or a single lifetime purchase. Slo runs on iPhone, Android and Mac, and 180 sounds play free at slonoise.com with no account.

Plenty of what Calm offers is absent here. Slo has no Sleep Stories, no guided meditation, no sleep tracking, no adaptive audio, no alarm, no recorder and no voice.

With Calm you start from a library someone else filled. Its sleep section includes 300+ Sleep Stories alongside music, meditation, and soundscapes, among them white, green, and brown noise. Calm runs on compatible Apple and Android devices and on the web.

Does Calm have a mixer?

Not one we could find. Calm’s official product and support pages document soundscapes and background scenes, and no manual layer mixer like Slo’s appears in them. Its audio is still useful; you’re picking a finished track from it.

Slo’s mixer has no cap on layers. Put a steady base underneath, one of its 5 brown noise tracks, add rain on top, then pull either one down until the sound sits behind the room and you stop hearing it as two things.

If fiddling with levels feels like one more chore before bed, Calm’s ready-made tracks are the easier night. If a single sound bores you and finished tracks never quite match your room, the mixer earns its minute.

Sleep Stories and meditation: Calm is the clear fit

Calm documents more than 300 Sleep Stories, plus meditation, music, and other wellness content. Some of it opens without Calm Premium, and the wider library needs paid access. Access and prices move by region and by where you buy, so check the current offer on your own device; a number in a comparison article ages badly.

Slo has no narrated Sleep Stories and no guided meditation, and that gap is a gap. Pick Slo when recorded ambient sound is the whole product you want, and pick Calm when you want a wellness catalogue around the sound.

Offline use and platforms

Calm officially supports downloading Sleep Stories for offline listening. In the Slo app, each sound downloads on first play and stays on the device, and an offline page lets you fetch any sound or the whole library in one action, with no premium gate, after which a saved mix plays with no connection. The browser player is a different thing and always needs the network.

For access, Calm documents iOS, Android, and web experiences. Slo runs on iPhone, Android and Mac, and its browser tools play 180 sounds free. In the browser the timers stop at 60 minutes, so the app is the version that reaches 24 hours.

Which should you choose?

Choose Slo if:

• Recorded ambient sound, presets and a mixer with no layer cap are what you’re after.
• A timer that runs to 24 hours and fades out matters more to you than guided content.
• Paying once appeals more than another monthly charge.
• Trying 180 sounds free in a browser appeals before you install anything.

Choose Calm if:

• Sleep Stories, meditation and music are part of how you wind down.
• You’d rather open a finished session than build one.
• Downloading Sleep Stories for offline listening matters to you.

Still weighing up the renewal? Our guide to Calm alternatives sorts the options by what people actually opened Calm for, which isn’t always the sound library.

Frequently asked questions

Does Calm have brown noise and white noise?

Yes. Its official sleep page lists soundscapes that include white, green, and brown noise.

Does Calm have a sound mixer like Slo?

Calm’s own pages document soundscapes and background scenes, and we found no official layer mixer there like the one in Slo. Interfaces change, so look at Calm itself if mixing is what decides this for you.

Can I use either product on the web?

Yes. Calm documents web access, and Slo’s browser player runs 180 sounds free with no account at slonoise.com, with a volume on each layer and timers of 15, 30 or 60 minutes.

Which app is better for meditation?

Calm, without much argument. Guided meditation sits at the center of the library it documents. Slo has none at all, and nothing in it speaks; it plays recordings.

Official sources checked July 31, 2026

• Calm: sleep content and soundscapes
• Calm: Sleep Stories library and offline downloads
• Calm: Premium offerings
• Calm: content available without Premium
• Calm: supported apps and platforms
• Calm: how to check current subscription pricing
• Slo app source, version 3.132 (sound list, timer, fade-out and store products), and the slonoise.com sound catalogue, reviewed September 14, 2026

Related guides

• Calm alternatives in 2026
• Slo vs Headspace
• Best sleep sound apps in 2026
• How to create a sleep soundscape
• Best sounds for deep sleep