Free online RTX to MID converter

Older Nokia-style ringtones may be stored as RTX text, while a music editor or playback device may require a MIDI file. Converting the note sequence to MID makes it usable as a MIDI performance; it does not turn the ringtone into a recording of a particular instrument.

What the RTX format is

RTX commonly contains ringtone data written in RTTTL-style text: a tune name, default note settings, and a sequence of notes and rests. It is associated with mobile-phone ringtones and can be opened in a plain-text editor; files often contain three colon-separated sections, such as name:d=4,o=5,b=125:c,e,g. The extension alone does not guarantee this format, so check that the file contains readable ringtone notation before converting.

What the MID format is

MID is a filename extension for Standard MIDI Files. It stores musical events such as note pitches, durations, and timing rather than recorded sound. MIDI is useful for editing or playing a melody in music software and for devices that accept MIDI; the playback instrument depends on the receiving software or device.

How to convert RTX to MID

Online on 101convert.com

1. Upload the RTX file or select several files for batch conversion.
2. Choose MID as the output format and start the conversion.
3. Download the converted file or files. The page shows the per-file size limit.

Offline with desktop software

For RTTTL-style RTX files, a small Python script using the open-source mido library can write a MIDI file on Windows, macOS, or Linux. Install the dependency with python -m pip install mido (use python3 in place of python if that is the Python command on your system), then save this as rtx_to_mid.py:

import re, sys
from mido import MidiFile, MidiTrack, Message, MetaMessage, bpm2tempo

src, dst = sys.argv[1:3]
name, settings, melody = open(src, encoding="utf-8-sig").read().strip().split(":", 2)
cfg = dict(item.split("=", 1) for item in settings.split(","))
bpm = int(cfg.get("b", 63))
default_len = int(cfg.get("d", 4))
default_oct = int(cfg.get("o", 6))
semitone = {"c": 0, "d": 2, "e": 4, "f": 5, "g": 7, "a": 9, "b": 11}
events = []
tick = 0

for token in melody.replace("\n", "").split(","):
    m = re.fullmatch(r"(?i)(\d+)?([a-gp])(#?)(\d+)?(\.)?", token.strip())
    if not m:
        raise ValueError("Unsupported RTTTL note: " + token)
    length = int(m.group(1) or default_len)
    note = m.group(2).lower()
    duration = round(480 * 4 / length * (1.5 if m.group(5) else 1))
    if note != "p":
        octv = int(m.group(4) or default_oct)
        pitch = 12 * (octv + 1) + semitone[note] + (1 if m.group(3) else 0)
        events.append((tick, 1, Message("note_on", note=pitch, velocity=90)))
        events.append((tick + duration, 0, Message("note_off", note=pitch, velocity=0)))
    tick += duration

events.sort(key=lambda event: (event[0], event[1]))
midi = MidiFile(ticks_per_beat=480)
track = MidiTrack()
midi.tracks.append(track)
track.append(MetaMessage("set_tempo", tempo=bpm2tempo(bpm)))
previous = 0
for at, priority, message in events:
    message.time = at - previous
    track.append(message)
    previous = at
midi.save(dst)

Run it with python rtx_to_mid.py input.rtx output.mid. The script handles comma-separated RTTTL notes, rests, sharps, octave and note-length overrides, and dotted notes; it does not convert unrelated file types that happen to use the RTX extension.

Quality and compatibility

RTTTL-style ringtone data usually describes a single melody, so the resulting MIDI contains note events rather than the original ringtone’s recorded sound or a guaranteed instrument sound. If the RTX file is not readable ringtone notation, this method will not interpret it; confirm the file’s actual contents and format before conversion.