Ship Invoices as Fast as You Ship Code
You automate everything else — why is invoicing still manual? BillFast keeps invoicing at the command-line level of speed: open page, fill fields, download PDF. No OAuth, no onboarding wizard, no seat pricing.
PO numbers, milestone line items, and Net 15/30 terms are built in. Your invoice history lives in localStorage, and yes — there's a dark mode.
Create your free invoice →- PO number field for enterprise clients and agencies
- One-tap Net 7/15/30 payment terms with automatic overdue tracking
- Runs entirely client-side — your billing data never leaves your machine
Frequently asked questions
Does BillFast have an API?
Not yet — but invoices are shareable as self-contained links (the data is encoded in the URL), which makes programmatic sharing trivial.
Can I bill sprints or milestones?
Each line item takes a description, quantity, and rate — 'Sprint 3 (2 weeks)' or 'Milestone 2: checkout flow' both fit naturally.
Is my data private?
Everything runs in your browser. No server storage, no tracking of invoice contents.
Dark mode?
Of course. Toggle is top-right.