Create printable and easily-recovered versions of your most valuable plain text documents to entrust with your secret keeper.
This utility is inspired by txt4print, a command line tool for creating physical backups of small text files. In contrast to the original utility, fidelius works on Windows.
fidelius aims to ease backup & disaster recovery of plain text by means of a physical document. In short, we can turn plain text like this:
Our Father in heaven, hallowed be your name.
Your kingdom come, your will be done, on earth as it is in heaven.
Into a PDF that will contain something like this:
File name: golden.txt
File size: 727 bytes
File sha256: 28f483bf5400864700aca420fc4c7ba97501f237b2dd9cd677d6cfeb8c9566ef
Printed: 2025-11-19 22:31:35
BEGIN FILE =====================================================================
0001 Our·Father·in·heaven,·hallowed·be·your·name.¶ 2F0C
0002 Your·kingdom·come,·your·will·be·done,·on·earth·as·it·is·in·heaven.¶ B4EE
Here is a complete PDF example, which includes the entire header: golden.pdf
- Monospace font with substitution of non-printable characters
- Explicit marking of whitespace and newlines
- Per-line CRC-16-IBM checksums
- Whole-file SHA-256 checksum
- Configurable page size & margins
- Built-in editor for recovery
- CI/CD pipelines
- Build attestation
- Multi-page documents
- @lobaro/txt4print, for the original tool. Their README has some great advice and is worth a look.