Two Office Suites, One Detection Engine
Organizations choosing between Microsoft Office and LibreOffice for document workflows face a practical question: can I get the same PII anonymization quality in both?
With anonym.legal, the answer is yes. Both the LibreOffice Extension and the Office Add-in connect to the same backend detection engine — the same 285+ entity types, the same hybrid regex + NLP detection, the same 48-language support. The differences are in platform-specific integration details, not detection quality.
Side-by-Side Comparison
| Feature | LibreOffice Extension | Office Add-in |
|---|---|---|
| Detection engine | Presidio hybrid (regex + spaCy NLP) | Presidio hybrid (regex + spaCy NLP) |
| Entity types | 285+ | 285+ |
| Languages | 48 | 48 |
| Methods | Replace, Mask, Redact, Hash, Encrypt | Replace, Mask, Redact, Hash, Encrypt |
| Word processing | Writer (format preserved) | Word (format preserved) |
| Spreadsheets | Calc (cell-based) | Excel (cell-based) |
| Presentations | Impress (text objects) | PowerPoint (text objects) |
| Preview | Up to 50 entities | Up to 50 entities |
| Per-entity operators | Yes | Yes |
| Presets | Yes (synced) | Yes (synced) |
| Encryption keys | ZK-wrapped, synced | ZK-wrapped, synced |
| Authentication | ZK (Argon2id) | ZK (Argon2id) |
| Platforms | Windows, macOS, Linux | Windows, macOS, Web, iPad |
| File format | .oxt extension | Office Add-in manifest |
| Offline mode | No (API required) | No (API required) |
| Cost | Same token pricing | Same token pricing |
Format Preservation: Writer vs. Word
Both extensions preserve formatting during PII replacement, but through different document APIs.
LibreOffice Writer (UNO API):
- 7 font properties: family, size, weight, style, color, underline, strikethrough
- 4 paragraph properties: alignment, first-line indent, left margin, right margin
- Styles, tables, and document structure preserved
Microsoft Word (Office.js API):
- Font properties: name, size, bold, italic, color, underline, strikethrough, highlight
- Paragraph properties: alignment, indentation, spacing, line spacing
- Tracked changes, headers, footers, and styles preserved
The result is functionally equivalent: PII text is replaced while all surrounding formatting remains intact.
Where They Differ
Platform availability
The Office Add-in runs on Windows, macOS, Office Online, and iPad — covering the full Microsoft 365 ecosystem. The LibreOffice Extension runs on Windows, macOS, and Linux — covering the three desktop operating systems where LibreOffice is installed.
LibreOffice has the advantage on Linux, where Microsoft Office is not available. The Office Add-in has the advantage on iPad and in browser-based Office Online workflows.
Installation
LibreOffice: Download .oxt file, double-click to install. No marketplace, no admin approval for personal use.
Office Add-in: Sideload via manifest URL or deploy through Microsoft 365 admin center. Enterprise deployment uses centralized admin controls.
Enterprise deployment
Microsoft Office has stronger enterprise management: Microsoft 365 admin center deployment, Group Policy configuration, Intune management. LibreOffice enterprise deployment relies on system administrators distributing the .oxt file through their own channels.
Document format ecosystem
Microsoft Office dominates in corporate environments where .docx/.xlsx/.pptx are standard. LibreOffice is prevalent in government agencies (especially in Europe), educational institutions, and organizations avoiding Microsoft licensing. Both suites handle each other's formats, but each performs best with its native format.
Cross-Platform Consistency
The critical advantage of using anonym.legal for both suites: detection results are identical.
If you process a document in Writer and the same text in Word, the same entities are detected with the same confidence scores. Presets created in one platform work in the other. Encryption keys sync across both.
This eliminates the compliance risk of using different detection engines for different document types — a common problem when organizations use one redaction tool for Word and a different tool for LibreOffice.
When to Use Which
Choose LibreOffice Extension when:
- Your organization standardizes on LibreOffice
- You work on Linux
- You need no-cost office software with enterprise-grade PII redaction
- Government or public sector requirements mandate open-source software
Choose Office Add-in when:
- Your organization uses Microsoft 365
- You need iPad or Office Online support
- Enterprise deployment through Microsoft 365 admin center is required
- Documents must stay in .docx/.xlsx/.pptx format throughout the workflow
Use both when:
- Your organization has mixed environments
- Different departments use different suites
- You receive documents in both ODF and OOXML formats
With preset sync and shared encryption keys, switching between platforms is seamless.
Getting Started
- Download LibreOffice Extension — .oxt file, double-click install
- Install Office Add-in — Microsoft 365 integration
- Compare all platforms — Full feature comparison
Both use the same token-based pricing. Free tier: 200 tokens/month.
Sources:
- anonym.legal LibreOffice Extension documentation — verified feature parity
- anonym.legal Office Add-in documentation — feature reference
- GDPR Article 4(5) — pseudonymization definition; Recital 26 — anonymization scope