Anonymize in LibreOffice Writer, Calc & Impress
Open-source office suite, enterprise-grade privacy. Our native LibreOffice extension brings PII detection and anonymization to Writer, Calc, and Impress.
Works Across LibreOffice
One extension for Writer documents, Calc spreadsheets, and Impress presentations. Full sidebar integration with format preservation.
LibreOffice Writer
Documents, contracts, reports — with full format preservation
LibreOffice Calc
Spreadsheets, data tables — cell-based processing
LibreOffice Impress
Presentations, slides — text object extraction
Key Benefits
Work In-Place
No copy-paste needed. Anonymize directly in LibreOffice via the integrated sidebar panel.
Format Preservation
Writer documents retain all formatting — bold, italic, fonts, colors, paragraph styles. Only text content changes.
Secure Processing
Documents stay on your machine. Only text is sent to our encrypted API for entity detection and anonymization.
Zero-Knowledge Login
Your password never leaves your device. Optional ZK authentication with XChaCha20-Poly1305 encryption.
Learn about Zero-Knowledge SecurityCore Features
PII Detection
- Detect 285+ entity types (names, emails, SSN, IBAN, credit cards, etc.)
- Hybrid detection: regex patterns + NLP for maximum accuracy
- Multi-language support (48 languages including RTL)
- Custom entity recognition with regex or deny lists
Anonymization Methods
- 5 methods: Replace, Mask, Redact, Hash (SHA-256), Encrypt (AES-256-GCM)
- Reversible encryption with ZK-wrapped personal keys
- Per-entity operator configuration (different methods per entity type)
- Chunked processing (8,000 char chunks) for large documents
Advanced Features
Preview Dialog
Review up to 50 detected entities before anonymizing. Select, deselect, or change methods per entity before committing.
Presets
Save and reuse anonymization settings. Presets sync across devices including entity types, methods, and score thresholds.
Reversible Encryption
Encrypt PII with AES-256-GCM and decrypt later. ZK-wrapped keys auto-load from your account with session persistence.
Per-Entity Operators
Configure different anonymization methods for each entity type. Hash names, encrypt emails, mask phone numbers — all in one pass.
Cross-Device Sync
Presets, custom entities, and encryption keys sync across all your devices every 5 minutes via your account.
48 Languages
Full multi-language support including Arabic, Hebrew, Chinese, Japanese, and Korean. RTL languages fully supported.
Document Support
Writer
Full text extraction, selection-based processing, and format preservation (7 font + 4 paragraph properties).
Calc
Cell-based processing with tab-separated text extraction. Process entire sheets or selected ranges.
Impress
Slide text object processing. Extract and anonymize text from all shapes and text boxes across slides.
System Requirements
Works on Windows, macOS, and Linux with LibreOffice 3.0 or later.
Supported Platforms
- • LibreOffice Writer 3.0+ (Windows, macOS, Linux)
- • LibreOffice Calc 3.0+ (Windows, macOS, Linux)
- • LibreOffice Impress 3.0+ (Windows, macOS, Linux)
What You Need
- • Python 3.10+ (bundled with LibreOffice on most platforms)
- • anonym.legal account (free or paid)
- • Internet connection for API access
- • PyNaCl (optional, for ZK authentication and Encrypt method)
Frequently Asked Questions
Which LibreOffice applications are supported?
Writer, Calc, and Impress. Writer has full feature support including format preservation. Calc processes cells as tab-separated text. Impress extracts text from slide objects.
How do I install the extension?
Download the .oxt file and either double-click it, or go to Tools > Extension Manager > Add in LibreOffice. Alternatively, run python3 build.py --install from the source directory.
Does it preserve document formatting?
Yes, in Writer documents. The extension preserves 7 font properties (bold, italic, underline, strikethrough, font name, size, color) and 4 paragraph properties (alignment, first-line indent, left margin, right margin).
What is Zero-Knowledge authentication?
ZK auth means your password never leaves your device. Instead, a cryptographic proof is sent to our server using XChaCha20-Poly1305 encryption with Argon2id key derivation. Optional — standard email/password login also available.
Can I use it offline?
No. The extension requires an internet connection to communicate with the anonym.legal API for entity detection and anonymization. For offline use, see anonym.plus.
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Get Started with LibreOffice Extension
Free for all plans. Install the .oxt extension in under a minute.