I made an invoice generator with zero paywalls. The catch is there's no catch.

Try searching "free invoice generator." Every result is the same trap: you fill in the whole invoice, hit download, and then comes the signup wall, the watermark, or the "free trial." The invoice is the bait.

That pattern annoyed me enough to build DocForge (thedocforge.com), where free actually means free:

• Fill a form, watch the live preview update, download a print-ready PDF

• Everything is generated in the browser. Nothing is uploaded, nothing is stored

• No account, no email, no watermark, ever

It started as one invoice tool and grew into eight: receipts, quotes, purchase orders, pay stubs, credit notes, delivery notes, letterheads. Plus trade-specific invoice pages (photographer, contractor, tutor...) and country versions with the right tax labels (VAT, GST, sales tax).

The business model: the tools are monetized with a discreet ad and affiliate links to accounting software. That's it. The bet is that removing 100% of the friction generates enough volume to make ads work, while everyone else optimizes for email capture.

The privacy angle turned out to be a bigger deal than expected. Invoices contain names, addresses and amounts, and most generators upload all of that to their servers. In-browser generation removes the question entirely.

Curious what this community thinks: is "radically free + ads" a sustainable model for utility tools, or does it cap out too low?