OnStem vs Stemulator
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
OnStem
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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.
Stemulator
This app uses advanced audio separation models to extract individual elements from any song with studio-quality precision. It offers modes for producers to download stems and for musicians to play along with real-time mixing and chord mapping.
- Extract up to 18 stems per track
- Producers Mode for stem downloads
- Musicians Mode for real-time mixing
- Generate MIDI chord maps
- Real-time chord mapping and waterfall MIDI piano
- Supports major audio formats for import and export
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Stemulator is the ultimate stem separation app for producers, musicians, DJs, and audio enthusiasts. Using advanced audio separation models, Stemulator extracts individual elements from any song with studio-quality precision. SEPARATE UP TO 18 STEMS PER TRACK • Vocals: Lead Vocal, Backing Vocal • Rhythm: Drums, Bass, Drumless • Drums: Kick, Snare, Hi-Hat, Toms, Cymbals • Instruments: Piano, Guitar, Strings, Keys/Synths, Winds, Ensemble • Full Mix: Instrumental • MIDI Chord Map TWO POWERFUL MODES Producers Mode — Download every stem for your projects: • Download separated stems in WAV, AIFF, or MP3 • Separate drums into Kick, Snare, Hi-Hat, Toms & Cymbals • Isolate instruments: Piano, Guitar, Strings, Keys/Synths, Winds • Separate vocals into Lead & Backing • Generate MIDI chord maps from any track Musicians Mode — A full DAW-style mixer for playing along: • Mute, solo & mix individual stems in real time • Adjust key & tempo with studio-quality pitch shifting • Real-time chord mapping & waterfall MIDI piano synced to playback • Real-time tabs for guitar, piano, & bass • Real-time capo recommendations for guitarists • Beat loop — 4, 8, 16, 32 or 64 beats, quantized to the beat grid • Synced metronome with multiple click sounds • Export chord charts as PDF or MIDI files • Export your custom mix as WAV, AIFF, or MP3 REAL-TIME CHORD MAPPING Stemulator analyzes the harmonic progression of your track and maps out every chord change—synced to playback in real time. Follow along as you play, export as a printable PDF chord chart, or download as a MIDI file for your DAW. STUDIO QUALITY OUTPUT Stemulator delivers the most advanced audio separation available — professional-grade stems with unmatched clarity and precision. Whether you're creating remixes, practicing along with isolated instruments, or producing new tracks, you'll get clean, artifact-free stems ready for your workflow. SUPPORTS ALL MAJOR FORMATS Import your music in WAV, AIFF, MP3, FLAC, M4A, or OGG format. Export your separated stems in high-quality WAV, AIFF, or MP3 for maximum flexibility in your DAW or audio editor. PERFECT FOR: • Producers – Sample and remix with clean, separated elements • Musicians – Mix stems, transpose key & tempo, follow chord maps • DJs – Create unique mashups and transitions • Karaoke – Remove vocals from any song instantly • Educators – Isolate specific parts for music lessons • Transcribers – Hear individual instruments clearly FOUR FLEXIBLE PLANS Free: Try Stemulator with 3 free stem separations Professional: 10 Stemulations per month, 5-stem separation Studio: Unlimited Stemulations, studio quality, 6-stem separation + Drumless, chord map generation & PDF export Audiophile: Full access to all 18 stems including individual drum separation, vocal separation, instrument isolation, MIDI chord export & real-time chord mapping HOW IT WORKS 1. Upload any song from your library 2. Choose Musicians or Producers mode 3. Stemulate your audio 4. Mix, play along, or download your stems Whether you're isolating a guitar solo to learn, removing vocals for karaoke night, transposing a song to your key, or extracting drums for your next production, Stemulator makes professional stem separation accessible to everyone. Download Stemulator today and unlock the individual elements hidden in your favorite music. Terms of Use: https://stemulator.app/terms.html
Screenshots
Verdict
The clearest difference is ads: Stemulator at none against OnStem's shown. Stemulator also leads on update cadence (every 9 days vs every 3 weeks) and device support (4 vs 2). On price and in-app purchases 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
Both are free to download. OnStem sells 4 in-app purchases, starting at $0.99 per month and Stemulator sells 8 in-app purchases, starting at $4.99 per month. Whichever you choose, the download price is not the number that matters.
OnStem ships an update every 3 weeks, Stemulator every 9 days. Both last shipped on November 5, 2026.
| Parameter | OnStem | Stemulator |
|---|---|---|
| Price | Free | Free |
| Rating | — | 4.7 (13 ratings) — better |
| Positive reviews | — | 94.4% of reviews |
| Number of ratings | — | 13 — better |
| Update frequency | Every 3 weeks | Every 9 days — better |
| Ads | Yes | No — better |
| In-app purchases | Yes | Yes |
| Monetization | — | Free with in-app purchases |
| Devices | iPhone, iPad | iPhone, iPad, iPod, Mac — better |
| Requires iOS | 18.0 | 15.0 — better |
| Further details — not scored | ||
| Size | 137 MB | 60 MB |
| Age rating | 4+ | 4+ |
| Developer | 阳 刘 | Stemulator LLC |
In-app purchases
OnStem
- OnStem Pro – Monthly$0.991 Month
- OnStem Pro – Quarterly$2.393 Months
- OnStem Pro – Annual7 Days trial$8.991 Year
- OnStem Pro – Lifetime$9.99
Stemulator
- Professional$4.991 Month
- Studio$9.991 Month
- Audiophile$19.991 Month
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- Production$29.991 Month
- Professional (Annual)$39.001 Year
- Studio (Annual)$79.001 Year
- Audiophile (Annual)$149.001 Year
- Production (Annual)$249.001 Year








