.FLP File Format

Introduction

These are the projects saved by FL Studio 21 and the releases after it, which are named by year from FL Studio 2024. The file has UTF-16LE text and multiple arrangements of up to 500 tracks, but some records have grown and at least one new event breaks a long-standing rule. These are the newest files and the least studied: what follows comes from open-source readers that are still catching up.

Structure

The file is a 14-byte header chunk and a data chunk holding one long stream of events. What sets these files apart:

• Playlist items. FL Studio 21 lengthened each playlist item record from 32 bytes to 60. A proposed change to PyFLP reports 80-byte records from FL Studio 2024 and 2025, and another reader, flpkit, reports 88-byte records in files it labels FL Studio 2026. PyFLP chooses the record layout from the event’s length rather than from the version, which copes with sizes it already knows.
• Event sizes. In earlier files an event’s ID always gives the size of its value. In files from FL Studio 2024 on, event 172 does not follow that rule. Two readers disagree on its length (one byte or three bytes), and both readings consume the same bytes in the examples published so far, so the question is open.

Other fields may have changed without being noticed yet. A reader for these files should check the version, skip events it does not know by their length, and not assume fixed record sizes.

Telling it apart

The FL Studio version text event (199) has a major number of 21 or higher. The length of the playlist items event (233) is a multiple of 60, or of the longer record sizes, rather than 32.

Variants

• FruityLoops 1 to FL Studio 5 – early projects: single-byte text, old tempo events and the 1999 layout
• FL Studio 6 to 11.4 – single-byte text, with volume and pan on a newer scale
• FL Studio 11.5 to 12 – every string but the version switches to UTF-16LE
• FL Studio 20 – multiple arrangements, 500 playlist tracks and 125 mixer inserts
• FL Studio 21 and later – 60-byte and longer playlist records, and an event that breaks the size rule

Links