I built an offline invoice generator in a single HTML file

João Cunha — Tue, 19 May 2026 18:12:45 +0000

I recently built a small offline invoice generator using a single HTML file.

The idea was simple: I wanted something that could run directly in the browser without login, without a backend, and without a subscription.

The tool lets you:

Add your business details
Add client details
Add invoice items
Calculate subtotal, tax, and total
Preview the document
Save it as a PDF

Why offline?

Most invoice tools are either online platforms, subscription-based, or require creating an account. For simple use cases, that can feel like too much.

So I wanted to test a different approach:

download once, open in the browser, use whenever needed.

This is not accounting software. It is just a lightweight document generator for simple client documents.

After building the invoice generator, I also packaged it with a quote generator and receipt generator as a small Freelancer PDF Kit.

If you want to check it out, here it is:

Gumroad: https://jctools.gumroad.com/l/freelancer-pdf-kit

Payhip: https://payhip.com/b/M58nJ

I’d appreciate any feedback on the idea, positioning, or what would make this more useful.

DEV Community: João Cunha

I built an offline invoice generator in a single HTML file