Open Source Alternatives to YNAB

Firefly III is a free and open-source personal finance manager designed to help you gain control over your financial life. With its comprehensive features, you can easily manage your transactions, budgets, and financial reports, all in one place.

• Full transaction management: Firefly III features a double-entry bookkeeping system. You can quickly enter and organize your transactions in multiple currencies.
• Import data from any source: A special Data Importer helps you import data into your Firefly III administration.
• Advanced rule engine: Use rules to quickly convert shorthands to detailed transactions or clean up your bank's abysmal CSV files.
• Budgets, categories, and tags: Name your poison. Do you like to work with tags? Need to budget your expenses? Want to categorize all of your hobby expenses? Look no further. Firefly III supports all kinds. Budgets can be expanded with limits in multiple currencies, so you can budget both your daily household expenses and what you spend in Imperial Credits when visiting Tatooine.
• Informative reports: Firefly III has advanced reporting capabilities, showing your expenses per week, month, or year. It can also help you audit your accounts with detailed list views or compare budgets or tags.
• JSON REST API: For advanced and mobile users, Firefly III features an expansive JSON REST API that allows you to tap into Firefly III's most important features. Create transactions, manage categories, and get chart data from any app or system.

Firefly III is a robust tool that offers a wide range of features to help you manage your personal finances with ease and efficiency.