LFM File

What are LFM files and how to open them

Are you having problems opening a LFM file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your LFM files.

What is a LFM file?

A .LFM file is a Lazarus Form file.

A Lazarus Form (.LFM) file is a plain text file used by the Lazarus IDE to store the layout and properties of a form (also known as a GUI window or dialog) in an application. It describes which visual components appear on the form, their positions and sizes, captions, and other configuration details. When you design a form - dragging buttons, setting labels, and defining how it looks - these settings are saved in the .LFM file. The file works together with a Pascal unit file (.pas) that contains the code implementing the logic behind those components.

The Lazarus IDE writes .LFM files whenever you save the design of a form in a project. These files are version-controlled, human-readable, and intended for editing by the IDE rather than by hand (though you can view or edit them in a text editor when needed). During compilation, Lazarus may compile the .LFM into a resource that the executable loads at runtime so the form shows up as designed. It is not executed directly; instead the IDE or compiler reads this file to generate resources and associate form layout with the compiled Pascal code.

Internally, .LFM files begin with the ASCII keyword object at offset 0 and contain recognizable text strings such as LCLVERSION, OBJECT, HEIGHT, WIDTH, LEFT, and CAPTION, among others. These serve as markers of properties and objects used in the Lazarus Component Library.

How to open LFM files

We have identified one LFM opener that is compatible with this specific type of LFM file.

Programs that open Lazarus Form files

Last updated: August 7, 2026

Various apps that use files with this extension

These apps are known to open certain types of LFM files. Remember, different programs may use LFM files for different purposes, so you may need to try out a few of them to be able to open your specific file.

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