"Zero-knowledge" gets used loosely in software marketing. We'd rather be specific about what it means for FillOnce than let the phrase do the work.
The problem FillOnce solves
Intake packets, grant applications, onboarding forms — the same personal details get typed dozens of times across PDF, Word, Excel and web forms. Existing browser autofill only handles web forms, and data this sensitive — names, addresses, ID numbers — shouldn't sit in an unencrypted store waiting to be reused.
What "zero-knowledge vault" means here, specifically
FillOnce encrypts your saved details with a key derived from your own passphrase. That specific design means the service itself doesn't hold a plaintext copy of your vault contents — the decryption key is derived from something only you know, not stored on FillOnce's servers as a recoverable secret.
The practical consequence: if you forget your passphrase, there is no "reset and recover your data" path, because there's no server-side copy to recover from. That's the trade-off zero-knowledge encryption always makes — stronger protection against a server-side breach, in exchange for the provider genuinely being unable to bail you out if you lose your own key.
What it fills, and how it stays under your control
FillOnce fills PDF, Word and Excel forms in addition to web forms — the formats generic browser autofill doesn't reach. Every field is shown for your review before anything is submitted; the tool fills the form, but you submit it.
Pricing
Free to try with no signup required, Pro at $9/month, Family at $14.99/month CAD.
FAQ
What does "zero-knowledge vault" mean for FillOnce?
Your saved details are encrypted with a key derived from your own passphrase, so FillOnce's servers don't hold a plaintext, recoverable copy of your vault contents.
What happens if I forget my FillOnce passphrase?
Because there's no server-side plaintext copy to recover from, there is no password-reset path that restores your existing vault data — this is the inherent trade-off of zero-knowledge encryption.
What form types does FillOnce fill?
PDF, Word, and Excel documents, in addition to standard web forms.
Does FillOnce submit forms automatically without my review?
No. Every field is shown for review before anything is submitted — you control what gets sent.
How much does FillOnce cost?
Free to try with no signup, Pro at $9/month, Family at $14.99/month CAD.
Try it
FillOnce is live at fillonce.app.