Introduction

Welcome to the KDBX compendium! This book is intended as an overview of the KeePass KDBX file format for developers implementing support for KeePass databases in their applications.

Notable KDBX format implementations

This book aims to compare different implementations of the KDBX file format, with direct references to the source code of each implementation. This is toidentify gotchas that developers might encounter.

Example: For Argon2, some implementations^{KP, KP2A, STBX} default to 2 lanes of parallelism, while some default to 4^{KPXC, KPDX, KPIU,}. Libraries generally don’t have a default, and require the caller to specify the number of lanes.

GUI applications

Application	Shortcode	Platforms	Language	Notes
KeePass	KP	Windows, (Linux, MacOS)	C#	No public git repo, will use unofficial mirror
KeePassXC	KPXC	Windows, Linux, MacOS	C++
Keepass2Android	KP2A	Android	Java
KeePassDX	KPDX	Android	Kotlin
KeePassium	KPIU	iOS	Swift
Strongbox	STBX	iOS, macOS	Objective-C, Swift

Libraries

Library	Shortcode	Language	Read support	Write support	Notes
pykeepass	PYKP	Python	KDBX3, KDBX4	?
keepass-rs	KPRS	Rust	KDB, KDBX3, KDBX4, KDBX4.1	experimental, KDBX4.1	maintained by the author of this book
kdbxweb	KDBW	TypeScript	KDBX3, KDBX4, KDBX4.1	KDBX3, KDBX4	seems unmaintained, last commit Dec 2024

Other resources

Conventions in this Document

All byte offsets are zero-based, so the first byte of a structure is at offset 0.
All byte ranges are non-inclusive, so the byte range 0-4 includes bytes at offsets 0, 1, 2, and 3, but not the byte at offset 4.
All lengths are in bytes, so a length of 4 means that the value occupies 4 bytes.
All hexadecimal numbers are prefixed with 0x, so the number 255 will be represented as 0xFF.