Comparison

OnStem vs Stemzel

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

OnStem

Features
Read full description

OnStem: AI Music Separation is an on-device AI-powered music separation tool that allows you to split audio tracks into individual stems with privacy and performance in mind. Powered by optimized local inference based on the open-source Spleeter project, OnStem performs all audio processing entirely on your device, without uploading files to any server. Key Features AI Music Separation Separate audio into 2 stems: Vocal and Accompaniment Separate audio into 5 stems: Vocal, Piano, Drums, Bass, and Accompaniment On-Device AI Processing All processing runs locally using on-device AI models No audio files are uploaded or shared Your content stays private on your device Optimized for Long Audio Custom optimizations allow processing of very long audio files Designed for stability and efficiency on mobile devices Multiple Export Formats Export separated tracks as MP3, WAV, M4A, or AAC Easily integrate with other audio tools and workflows Privacy First OnStem is a local-first application. All selected files are processed on your device only. No audio data or personal information is collected, stored, or uploaded. Subscriptions and Purchases OnStem offers both subscription plans and a one-time purchase option. Monthly subscription Quarterly subscription Annual subscription One-time lifetime purchase (where available) Payment will be charged to your Apple ID account at confirmation of purchase. Subscriptions automatically renew unless auto-renew is turned off at least 24 hours before the end of the current period. You can manage or cancel your subscription at any time in your Apple ID account settings. Prices may vary by region and are displayed before purchase. Legal Privacy Policy https://github.com/yangliu-1995/stemify-legal/blob/main/Privacy-Policy/EN.md Terms of Use https://github.com/yangliu-1995/stemify-legal/blob/main/Term-of-Use/EN.md OnStem is designed for creators who value privacy, performance, and on-device AI processing.

About

Stemzel

This app separates any song into vocals, drums, bass, and other instruments directly on your device. It offers on-device AI processing for privacy, with no cloud uploads or subscriptions required. Mix, mute, solo, and export individual stems or the full mix.

Highlights
  • On-device AI stem separation
  • Import audio from files or URL
  • Record and split audio instantly
  • Mute or solo individual stems
  • Built-in waveform scrubber
  • Export stems and full mix
Features
Read full description

Stemzel splits any song into four stems — vocals, drums, bass, and other instruments — entirely on your iPhone. No cloud uploads. No subscription. No account required. IMPORT YOUR AUDIO • File — pick from Files, iCloud Drive, or anywhere on your device • URL — paste a direct link to an MP3, M4A, or WAV file • Record — capture audio with your microphone and split it instantly MIX AND EXPORT • Mute or solo any stem to hear exactly what you want • Play back your mix with a built-in waveform scrubber • Export individual stems or your full mix to the Files app PRIVATE BY DESIGN Every split runs on your device using on-device AI. Your music never leaves your iPhone. No servers, no tracking, no ads. ONE-TIME UNLOCK Pay once, use Stemzel forever. Unlimited splits and downloads — no monthly fees, ever. PERFECT FOR • Musicians learning parts by ear • DJs and producers isolating elements • Karaoke and acapella practice • Remixing and sampling workflows • Anyone who wants stems without uploading to the cloud Stemzel is built for speed and privacy. Import a track, wait a moment while it separates, then mute the vocals, solo the drums, or export everything — all from your pocket. Questions or feedback? Visit stemzel.com/support

Screenshots

OnStem3 screens
Stemzel3 screens

Verdict

The call

The clearest difference is ads: Stemzel at none against OnStem's shown. OnStem's advantage is iOS requirement (18.0 vs 26.0). On price, in-app purchases and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. OnStem sells 4 in-app purchases, starting at $0.99 per month and Stemzel sells 4 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

Scorecard2 real differences · 7 level
OnStem versus Stemzel: the parameters behind the verdict, then further details
ParameterOnStemStemzel
PriceFreeFree
Rating—4.5 (2 ratings) — better
Number of ratings—2 — better
Update frequencyEvery 3 weeks—
AdsYesNo — better
In-app purchasesYesYes
Monetization—Free with in-app purchases
DevicesiPhone, iPad — betteriPhone
Requires iOS18.0 — better26.0
Further details — not scored
Size137 MB290 MB
Age rating4+4+
Developer阳 刘Mahija Kottapalli

In-app purchases

4 purchases

OnStem

Subscriptions3
  • OnStem Pro – Monthly$0.991 Month
  • OnStem Pro – Quarterly$2.393 Months
  • OnStem Pro – Annual7 Days trial$8.991 Year
One-time1
  • OnStem Pro – Lifetime$9.99
4 purchases

Stemzel

One-time4
  • Small Tip$0.99
  • Medium Tip$2.99
  • Large Tip$4.99
Show 1 more
  • Stemzel Unlock$7.99

Questions

Is OnStem free?
OnStem is free to download, with in-app purchases available.
Is Stemzel free?
Stemzel is free to download, with in-app purchases available.
Do OnStem or Stemzel have ads?
OnStem shows ads; Stemzel does not.

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