Noisli vs Slo: Focus Sound Mixer in Your Browser

Pick Noisli if you want your sound inside a place to work, with a Markdown editor, a session timer and a Chrome extension. Pick Slo if the sound is the only part you need, with 200+ sounds, 89 of them free, any number of layers at once and a work timer that fades out after up to 24 hours. On an Android phone, only Slo has an app you can install today.

How we compared. Every Noisli detail below is what its official features, apps and pricing pages say, checked July 31, 2026. We put neither app through a performance test. Slo is the app we make, and its figures come from the app source, version 3.132, on September 14, 2026. Neither app can guarantee better focus.

Slo vs Noisli at a glance

Choose	Best fit	Main tradeoff
Slo	200+ sounds, 89 free, in any number of layers, with a timer from 15 minutes to 24 hours	No built-in text editor or productivity statistics
Noisli	A browser-first focus workspace with sounds, timer, and writing tools	Smaller documented library; the complete web feature set is intended for desktop browsers

Neither app wins this outright. What decides it is whether sound is the whole thing you’re missing at your desk or one piece of a work setup you want to run from a single tab.

Noisli on Android

Noisli’s official apps page still links to an Android app. When we checked on 30 September 2026, that Google Play listing returned “not found” in the US, UK, German and Italian stores, and a Play search for Noisli only found a third-party copy. So you cannot install the Noisli Android app today. If Noisli puts up a new listing, this will change.

The iOS app is still on the App Store, and Noisli says the mobile app can play sounds offline.

You can also run Noisli as a web app or a Chrome extension. Its pricing page says the complete browser feature set is built for desktop and laptop browsers.

What Slo offers

The Slo app holds 200+ recorded sounds, and 89 of them cost nothing. You get 22 noise recordings across seven colors, five of those brown, along with 11 rain tracks, 9 water tracks and 5 fan tracks. The mixer takes as many layers as you want to add, each with a volume of its own, and it holds onto the balance for every combination you build. Save a mix and it exports as a file you can import on another device. The timer runs from 15 minutes to 24 hours and fades the sound out over 15 seconds to 2 minutes. Playback continues as a background audio service on iPhone and Android, so the sound keeps going while you work in another app. In the app, each sound downloads the first time you play it and stays there, so your mix runs with no network. Paying for the full library means a monthly or yearly subscription or a one-time lifetime purchase, and 180 of the sounds play free at slonoise.com with no account.

Slo has no text editor, no Pomodoro workflow, no browser extension and no session statistics. Noisli owns that side of the desk, and Slo only makes the sound.

What Noisli offers

Noisli puts an ambient sound mixer next to a set of work tools. Its official feature page documents 28 sounds on Pro, curated playlists, saved combinations, oscillation, shuffle, an advanced session timer, and a Markdown editor with nothing else on the screen.

The current Free web plan documents 16 sounds, 1.5 hours of streaming per day, three playlists, five saved favorites, a simple timer, and a simple text editor. Pro raises those limits and adds the rest of the tools. What you pay depends on your billing choice, your market and your platform, so check Noisli’s current pricing page before you buy.

If you need sound with no connection, Noisli’s iOS app is the route it documents for that. If the editor and the work-session controls are the point, use the web version.

Key differences

Sound library and discovery

Slo ships 200+ sounds, 89 of them free. Noisli documents 28 sounds on Pro and 16 on its Free web plan. The bigger number gives you more to try, while Noisli’s smaller set comes wrapped in playlists, saved combinations, oscillation and shuffle.

Neither total says anything about how good the recordings are or how well you’ll concentrate. It only changes how much material you have to work with.

Mixing workflow

Both apps let you run several sounds together and set each level. Slo also gives every sound its own page and puts its presets on the web, so you can try one sound or a finished mix straight from an article like this one. In Noisli the mixing sits closer to your account, your favorites and your playlists.

Productivity tools

If you want a Markdown editor and a work-session timer you can configure beside the sound, Noisli is the one that has them. Its timer statistics can also tell you how many focus sessions you finished.

Slo’s timer runs from 15 minutes to 24 hours and fades out before it stops. It isn’t a place to write or a Pomodoro tracker, and it doesn’t count your sessions.

Platforms

Both apps have an iOS download. Slo also has Android and Mac downloads, while Noisli covers the desktop through its browser app and Chrome extension. Which suits you comes down to whether you want a native Mac app or a workflow that lives in your browser tabs.

Access and pricing

Noisli publishes its Free, Pro and Business web limits in detail. Slo’s 180 browser sounds and its mixer open with no download and no account. Its full library in the app costs a monthly or yearly subscription or a one-time lifetime purchase, and 89 of its 200+ sounds stay free for anyone who never pays.

Which should you choose?

Choose Slo when you want 200+ sounds with 89 free, any number of layers at once, playback with no connection after a download in the app, or a Mac download. The browser mixer shows you that workflow in a tab.

Choose Noisli when you want the sound sitting next to your writing, your timed sessions, your playlists, your saved favorites and a browser extension. On Android, use Noisli in the browser, since its Play listing is gone.

If neither one fits, our Noisli alternatives guide holds a longer shortlist, and the best focus sound apps page covers the wider category.

Frequently asked questions

Is the Noisli Android app still available?

Not at the moment, as far as we can tell. Noisli’s apps page still links to an Android app, but that Google Play listing returned “not found” in the US, UK, German and Italian stores when we checked on 30 September 2026, and a Play search for Noisli only turned up a third-party copy. The iOS app, the web app and the Chrome extension still work. If Noisli publishes a new Play listing, this will change.

Is Slo or Noisli better for focus?

Slo only makes sound, with 200+ sounds, 89 of them free, any number of layers and a timer up to 24 hours. Noisli puts sound next to a timer, an editor, playlists and session statistics. Pick the setup you’ll really open every morning, then test it against silence on the same task.

Which has more sounds?

Slo ships 200+ sounds, 89 of them free, and 180 free in the browser. Noisli documents 28 sounds on Pro and 16 on its Free web plan. A bigger count gives you more to combine and says nothing about how the recordings hold up.

Is Noisli free in a browser, and is Slo?

Both play on the web, with different limits. Noisli’s Free web plan documents 16 sounds and 1.5 hours of streaming a day behind an account. Slo’s browser player opens 180 sounds, a mixer and 36 presets, and never asks you to sign in.

Does either app guarantee better focus or sleep?

No. Steady sound can cover a distraction or mark the start of work, and how well that lands depends on you, the task, the room and the volume. Neither app is a medical treatment.

Official sources checked July 31, 2026

• Noisli: features, apps, and plans and pricing. The Google Play listing and the App Store listing were rechecked on 30 September 2026.
• 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

• Best Noisli Alternatives in 2026
• Best Focus Sound Apps in 2026
• Best Sounds for Studying
• How to Use Sound Mixing

Filip Kowalski is the developer of Slo and writes about sound, sleep, and focus.