Best Open-Source Invoice Billing System for Freelancers
3 open-source options compared for invoice billing system for freelancers, with live GitHub data on each.
Last updated Repo data refreshed 25 Oct 20263 options
Our pick · SolidInvoice
Our pick is SolidInvoice because it offers an excellent balance of active maintenance and a highly permissive MIT license, which is ideal for freelancers seeking a simple and elegant invoicing solution. InvoiceShelf, an open-source invoicing solution for individuals and businesses, is also actively developed; however, SolidInvoice's MIT license provides more flexibility compared to InvoiceShelf's AGPL-3.0 license, which carries copyleft implications. Crater, an open-source invoicing solution for individuals and businesses, is not recommended for new projects due to its dormant maintenance status, which poses risks regarding security and long-term viability.
SolidInvoice vs InvoiceShelf vs Crater: side by side
★ 1,868 starsLicence: AGPL-3.0Last commit 25 Oct 2026Latest release 21 Oct 2026PHP
InvoiceShelf is a self-hosted web application designed to manage invoicing, track payments and expenses, and organize customer accounts. It empowers freelancers and small businesses to maintain full control over their business data, offering a focused workflow for financial management.
Best for: Freelancers and small businesses seeking a self-hosted invoicing solution to manage their finances, track expenses, and own their data, particularly those comfortable with the AGPL-3.0 license and managing a production-ready 2.x branch.
What's good
Provides a self-hosted platform, ensuring users retain full control and ownership of their business data.
Offers a focused workflow for creating invoices, tracking payments and expenses, and managing customer accounts.
Exhibits active development with recent updates and releases, indicating ongoing maintenance.
A live demo and detailed documentation are available for easy evaluation and setup.
Watch out for
Requires self-hosting, which necessitates technical knowledge for installation, configuration, and ongoing maintenance.
The AGPL-3.0 license can impose restrictions on commercial use or integration into proprietary systems compared to more permissive licenses.
The default 3.x branch is an alpha preview, requiring users to specifically target the 2.x release for production environments.
★ 8,355 starsLicence: AGPL-3.0Last commit 10 Aug 2024Latest release 6 Mar 2022PHP
Crater is an open-source web and mobile application that helps individuals and businesses track expenses, manage payments, and create professional invoices and estimates. The web application is built using Laravel and VueJS, while its mobile apps for Android and iOS are developed with React Native.
What's good
Offers a comprehensive set of features for invoicing, expense tracking, payment management, and creating estimates.
Includes dedicated mobile applications for both Android and iOS, providing flexible access for users on the go.
Provides extensive documentation covering installation steps, user guides, a developer guide, and API documentation.
Utilizes popular and robust web technologies such as Laravel and VueJS for its core web application.
Watch out for
The project is officially categorized as dormant, with no new releases since March 2022, indicating a lack of active development and official support.
Lack of ongoing maintenance suggests potential security vulnerabilities may not be addressed and compatibility with evolving operating systems or dependencies could become an issue.
Its AGPL-3.0 license, combined with the dormant status, may complicate community contributions or the merging of forks.
Could gradually become incompatible with newer systems or browsers over time due to the absence of continuous updates.
"Dormant" means no commit pushed to the default branch in the last 12 months. "Archived" means the maintainers have marked the repository read-only on GitHub. "Deprecated" means the project's README says it is deprecated or no longer maintained. Stars, licence, commit and release dates come from the GitHub API (GitLab for projects developed there) and are cached for up to 24 hours. The written analysis is AI-assisted and checked against that data.
Frequently asked questions
Are SolidInvoice, InvoiceShelf and Crater actively maintained?
SolidInvoice and InvoiceShelf are active: each has had a commit in the last 12 months (most recent: SolidInvoice on 24 Oct 2026, InvoiceShelf on 25 Oct 2026). Crater is dormant: no commit since 10 Aug 2024. Status is checked against GitHub daily.
What licences do SolidInvoice, InvoiceShelf and Crater use?
SolidInvoice: MIT; InvoiceShelf: AGPL-3.0; Crater: AGPL-3.0. Check each project's licence file before use.
Which is easiest to learn: SolidInvoice, InvoiceShelf or Crater?
By our estimate (1 = easiest, 5 = steepest): SolidInvoice 2/5, InvoiceShelf 3/5, Crater 2/5. SolidInvoice and Crater share the gentlest learning curve. This is ExploreGit's AI-assisted estimate, not a measured figure.
