The short answer: yes — this converter is a web page, so it runs in mobile Safari or Chrome exactly the way it runs on a desktop. Open it on an iPhone or an Android phone, tap to pick an audio file, and the notes come back as a .mid you can download. The pitch detection is identical because it runs on a fixed internal grid — a 22 050 Hz working rate, a 2048-sample window, one frame every 11.610 ms, a search window of 55–1800 Hz — none of which depends on the device. What genuinely changes on a phone is two things, not the notes: how the file gets in (no drag-and-drop; you tap to choose or share a file in) and the on-device cost (the whole file is decoded into the phone's memory and analysed on its CPU, so a long clip takes longer and a very large one can fail on a low-RAM phone). We measured the cost below.
1. What is identical, and what is not
The detector is just JavaScript running in the browser, so the result is the same algorithm on every platform. The grid it measures on is hard-coded:
- 22 050 Hz working sample rate — your file is resampled down to this, whether it started at 44.1k, 48k or 22.05k.
- 2048-sample analysis window, stepped 256 samples at a time.
- That gives one frame every 11.610 ms — about 86 frames per second of audio.
- The search runs from 55 Hz (A1) up to 1800 Hz, with polyphonic peaks allowed up to 4000 Hz.
None of those numbers are set per-device, so a melody you convert on a laptop returns the same notes as the same melody on a phone. The parts that do differ are everything around the math: the file picker, the browser's own codec support, and the CPU time it takes to churn through a long recording on a phone chip.
2. Getting the audio in (the part that is different)
On a desktop you drag a file onto the page. On a phone there is no drag, so the input flows through the OS file picker instead:
- Tap the chooser. The page opens the system file dialog — on iOS that is the Files app (iCloud Drive, On My iPhone, connected services); on Android it is the system file picker (Files, Google Drive, and so on).
- Or share a file in. From the Files app, Drive, or a messenger, use the share sheet and send the audio to your browser; it lands as the chosen file just the same.
- It must already be a file. There is no way to drag a whole folder in, and there is no live microphone capture — see Microphone to MIDI: what this converter does with a recording for the record-first workflow.
That is the entire difference on the input side. The conversion itself is the same page you already have open.
3. Format support depends on the mobile browser
The converter decodes audio with whatever the browser supplies, so which formats open is decided by the browser, not by us — the same rule that applies on desktop applies harder on a phone, because mobile browsers differ more than desktop ones:
- MP3, AAC (M4A) and WAV open on both iOS Safari and Android Chrome — these are the safe choices on a phone.
- OGG and FLAC support is uneven across mobile browsers; if a file will not open, it is a decoder gap, not a corrupt file.
- The fix is the same everywhere: export to WAV first. WAV to MIDI covers how to prepare the file, and MP3 to MIDI shows why a cleaner source reads better than a lossy one.
So before you blame the converter, check the format: on a phone, WAV or M4A is the path of least resistance.
4. The on-device cost, measured
The analysis runs on the phone's own CPU, not a server. To put a number on it we ran this site's own dsp.js detector on a desktop machine over clips of increasing length and timed the analysis pass:
| Clip length | Frames analysed | Desktop analyse time | Phone estimate (3–5× slower) |
|---|---|---|---|
| 10 s | 854 | 0.22 s | 0.7–1.1 s |
| 30 s | 2 576 | 0.55 s | 1.7–2.8 s |
| 60 s | 5 160 | 1.10 s | 3.3–5.5 s |
| 5 min (300 s) | ~25 800 | ~5.5 s | ~16–28 s |
The cost scales linearly with length — about 18 ms of compute per second of audio on the desktop we tested — because every frame is an independent FFT. A phone's CPU is typically 3–5× slower for this kind of work, so a one-minute clip costs a few seconds and a five-minute one can cost half a minute. The work is unavoidable: it happens on your device, so no server is doing it for you.
There is a second limit beyond time. The whole file is decoded into memory in full before the first frame is measured, so a very long or very high-bitrate file must fit in the phone's RAM at once. A short song is fine; a multi-hour recording is the case that can run a phone out of memory where a desktop would cope.
5. Does the result differ from desktop?
No — not the notes. Because the grid is fixed and the math is the same, the same take returns the same pitch list whether it was converted on a laptop or a phone. The only ways a phone result can look different are the two already covered: a format the mobile browser refused to decode (so you converted a WAV instead of the original OGG), and the timeout or memory ceiling on a very long file. Neither changes what a given frame is read as — only whether the file made it in at all, and how long it took. The same per-mode behaviour applies, so Mono vs poly is worth a read before you pick a mode on the smaller screen.
Questions people actually ask
Is there a native audio-to-MIDI app I should install on my phone?
No, and you do not need one for this. The converter is a web page, so the page itself is the app — open it in Safari or Chrome and it behaves the same as on desktop. There is nothing to download from an app store and nothing to upload, which is the same answer on Android or iOS.
Does it work offline on a phone?
Once the page is loaded, the analysis runs locally with no network, so you can convert without a connection. You do need a connection to load the page the first time; after that the file never leaves the device.
Why is it slower on my phone than on my laptop?
The detection is CPU work done on the device, and a phone chip is 3–5× slower at it than a laptop. The table above shows a 60-second clip takes about a second on a desktop and a few seconds on a phone — the same linear cost, a slower processor.
Can I just hold my phone up to an amp and convert?
Record the take first — a voice-memo or sound-recorder app — then open that recording in the converter; there is no live microphone capture in the browser. The recording becomes the file, and once it is a file you can run the whole conversion on the phone: Microphone to MIDI walks the record-first step.
Will a long file crash my phone?
It will not crash, but it can stall or fail to decode if it does not fit in memory, because the entire file is loaded at once. Keep phone conversions to song-length clips (a few minutes), and use WAV or M4A so the browser decodes them without trouble.
Open the page on your phone and drop a file in — the Audio to MIDI Converter runs entirely in your browser, so nothing is uploaded and the notes are yours to check. Once the pitches are right, How to clean up a converted MIDI before you use it walks the passes that turn a raw export into a usable part.
Related guides
- Microphone to MIDIWhat this converter does with a recording
- MP3 to MIDIWhy MP3 loses notes that WAV keeps
- WAV to MIDIHow to prepare the file before you convert
- Mono vs polyWhat each detection mode misses
- Clean up a converted MIDIThe 5 passes that turn a raw export into a usable part
- Song to MIDIWhat a full mix comes back as