Free online PDF to MIDI converter

Source format: PDF

PDF (Portable Document Format) is a fixed-layout document format created by Adobe and widely used for sharing documents that must look the same on any device. It is common for sheet music, scanned scores, lead sheets, and music books because it preserves page layout, notation, and engraving exactly as printed. However, a PDF usually stores music as page content or images, not as editable musical performance data.

Target format: MIDI

MIDI (Musical Instrument Digital Interface) is a performance data format used by musicians, composers, arrangers, and music software. A MIDI file stores notes, timing, velocity, tempo, and instrument information, but not audio. Its main advantages are small file size, easy editing in DAWs and notation software, and broad compatibility with virtual instruments and sequencers. MIDI is commonly used for composition, playback, transcription, and arranging.

How to convert PDF to MIDI

Converting PDF to MIDI is only reliable when the PDF contains digital music notation or a clean, high-quality score. If the PDF is a scanned image, you usually need optical music recognition first. Good desktop options include ScanScore, SmartScore, and Audiveris (free, open source). For occasional use, reputable online or cloud-based tools such as PlayScore 2 and PDFtoMusic can help, though results vary by score complexity and scan quality.

1. Check the PDF type. If the PDF was exported from notation software, conversion is more likely to succeed. If it is a scan or photo, expect more errors.
2. Open the PDF in an OMR-capable program. In ScanScore or SmartScore, import the PDF directly. In Audiveris, open the PDF and run recognition.
3. Review the recognized score. Correct notes, rests, clefs, key signatures, time signatures, voices, and barlines before exporting. This step is critical for usable MIDI output.
4. Export as MIDI. Use File → Export → MIDI or the equivalent export command in your software. Save the file as .mid or .midi.
5. Test the MIDI file. Open it in a DAW, notation program, or MIDI player to verify timing, instruments, and note accuracy.

If you already use notation software such as Finale, Sibelius, or MuseScore, a practical workflow is to convert the PDF to an editable score first, then export to MIDI. MuseScore does not reliably import a plain PDF as editable notation, so if the source is a PDF, use OMR software first or convert the score to MusicXML before bringing it into notation software for cleanup and MIDI export.

Quality limits and common problems

PDF to MIDI is not a direct one-to-one conversion in most cases. A PDF is visual, while MIDI is symbolic performance data, so the software must infer musical structure. That means:

• Scanned PDFs often produce recognition errors, especially with slurs, tuplets, dynamics, ornaments, and multiple voices.
• Complex orchestral scores are harder to convert than single-staff melodies or piano music.
• Lyrics, articulations, and layout may not transfer cleanly, and some notation details may be lost.
• MIDI playback may sound different from the original score because MIDI does not contain engraving or audio realism.

For the best results, use a clean digital PDF, choose a strong OMR tool, and expect to spend time correcting the recognition before exporting. If the PDF is only a scanned image and accuracy matters, manual transcription may be faster than trying to force a perfect conversion.

Best tool choices

• Audiveris — best free open-source option for OMR, especially for users comfortable with a technical workflow.
• ScanScore — user-friendly desktop option for importing PDFs and exporting editable notation or MIDI.
• SmartScore — strong desktop OMR tool for printed scores and multi-part music.
• PlayScore 2 — convenient cloud/mobile option for quick recognition and playback.
• PDFtoMusic — useful when the PDF was created from notation software and contains embedded music structure.

Important: if your PDF is just a scanned image, no converter can guarantee perfect MIDI output. The cleaner the score, the better the result.