LibreOfficeKit Converter Plugin #

A Flutter plugin that uses LibreOfficeKit to convert office documents directly on the device.

It allows you to transform DOC(-X), XLS(-X), PPT(-X) and many other formats into PDF (default) or another supported export format without external services, without internet, fully offline.

What is LibreOfficeKit? #

LibreOfficeKit (LOK) is the API of LibreOffice that can load and export documents programmatically.

This plugin packages LibreOffice and exposes LibreOfficeKit as a simple Flutter API.

LibreOffice version #

Platform builds are based on the following LibreOffice versions:

• Android → LibreOffice 26.8
• iOS → LibreOffice 24.8

Features #

• Convert documents fully offline
• No Cloud / no upload
• Works with many formats supported by LibreOffice
• Simple API
• Custom export filters supported

Supported conversions #

Anything that LibreOffice itself can open and export.

Common examples:

• DOC / DOCX → PDF
• XLS / XLSX → PDF
• PPT / PPTX → PDF
• ODT / RTF → PDF
• and many more

If LibreOffice can do it on desktop, LOK can do it here.

Installation #

Add the dependency in pubspec.yaml.

dependencies:
  libre_office_kit_converter_plugin: ^x.y.z

API #

init() #

Initializes LibreOfficeKit.

Must be called once before any conversion.

Internally this boots the LibreOffice runtime, loads fonts, registries and prepares the engine.

await converter.init();

convert() #

Converts a document into another format.

Parameters

Returns

Path to the produced file.

Important drawbacks #

Single document at a time #

LibreOfficeKit is not designed for parallel conversions in the same process.

If you start multiple conversions simultaneously, for example using Future.wait(), the documents will still be processed sequentially.

Application size #

LibreOffice is huge.

Expect the final application size to grow by ~600 MB depending on ABI and packaging strategy.

This is the price for fully offline document rendering.

Startup time #

Initialization may take noticeable time because fonts, configuration and registries must be loaded.

It is recommended to call init() early.

TODO / Roadmap #

• Ability to replace bundled compiled LibreOffice sources with custom builds
• More detailed error reporting

When should you use this plugin? #

Good if you need:

• offline conversion
• no dependency on cloud services
• maximum format compatibility

Bad if:

• app size is critical
• you need parallel conversions
• you only convert a very small subset of simple formats

License #

LibreOffice core is licensed under MPL