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Open-Source Anonymization: LibreOffice

How public sector organizations use LibreOffice with anonym.legal's extension for GDPR-compliant document anonymization.

March 10, 20269 minute read
LibreOffice extensiongovernment anonymizationpublic sector GDPRopen source complianceuniversity data protection

Open-Source Document Anonymization with LibreOffice

EU governments are moving to open-source software. Italy, France, Germany, and Spain have formal policies for it. Germany's Schleswig-Holstein moved 25,000 government PCs to LibreOffice in 2024. The French Gendarmerie runs 77,000+ workstations on GendBuntu. That is a Linux build with LibreOffice.

These agencies need GDPR-compliant anonymization. But most PII tools only work with Microsoft Office. That leaves a gap.

anonym.legal's LibreOffice Extension fills this gap. It detects 285+ entity types in Writer, Calc, and Impress. It runs on Windows, macOS, and Linux.

Why Open Source Suits the Public Sector

No vendor lock-in

Microsoft 365 costs money every year. LibreOffice is free. For agencies with many desktops, this is a big saving. But cost is not the only reason.

Open-source code can be checked. Any agency can read how it works. For bodies that hold citizen files, this is a legal need. It is not a choice.

Data stays in the EU

anonym.legal runs on Hetzner servers in Germany. No files leave the EU. With LibreOffice, there are no Microsoft cloud links. The whole workflow stays in one place.

Privacy by design

GDPR Article 25 asks for privacy built into every step. Copying text into an outside tool does not meet this rule. The extension works inside the editor. Removing personal details is part of the editing step. No extra apps are needed. No copy-paste risk.

Three Real-World Uses

Government DSAR responses

Citizens can ask for their records. Agencies must send them. But they must also hide any other person's details first.

With the extension:

  1. Open the reply in Writer
  2. Click Analyze
  3. Check the preview — keep the citizen's own details, remove all others
  4. Apply and send

The preview is key. DSARs need selective removal, not full blanket masking. Each entity can be accepted or skipped one by one.

University research files

Research teams must remove names before sharing study results. A project may include:

  • Calc sheets with names and contact details
  • Writer transcripts with quotes from study subjects
  • Impress slides with case details for a talk

One extension handles all three file types. Presets keep the same rules across the whole project.

Court document redaction

Courts that publish rulings must remove names, addresses, and other personal details. The extension has three modes:

  • Replace: Names become PERSON_1, PERSON_2 — the same label each time
  • Redact: Addresses are fully removed
  • Mask: Partial hiding for dates or case numbers where some context must stay

Writer keeps all formatting. Headers, footers, and numbered lists remain after any changes.

How to Deploy

Single user:

  1. Download the .oxt from anonym.legal/api/download/libreoffice
  2. Double-click and install
  3. Restart LibreOffice

IT team rollout: Share the .oxt via a network drive, Ansible, or SCCM. LibreOffice can install extensions from the command line with no user prompts. Teams can share presets through one anonym.legal account. This keeps rules the same for every user in the group.

GDPR Compliance Table

GDPR RuleHow It Is Met
Article 5(1)(c) — Data minimizationOnly found PII is changed; all other text stays the same
Article 25 — Privacy by designRemoval runs inside the editor, not in a separate tool
Article 32 — SecurityAES-256-GCM, zero-knowledge auth, ISO 27001 servers
Recital 26 — AnonymizationReplace, Redact, and Mask take content out of GDPR scope
Article 4(5) — PseudonymizationEncrypt mode gives reversible pseudonymization
BDSG Section 22Detection covers health, biometric, and ethnic origin fields

Get Started

  1. Download the extension — free
  2. Sign up at anonym.legal — free tier: 200 tokens per month
  3. Read the full docs

Paid plans start at EUR 3 per month for 1,000 tokens. Higher volumes are also available.

For agencies that handle many requests at once, see GDPR DSAR Batch Processing at Scale.

Sources

  • European Commission Open Source Software Strategy 2020-2023
  • Schleswig-Holstein government — 25,000 PC move to LibreOffice (2024)
  • French Gendarmerie — 77,000+ GendBuntu workstations (by 2019)
  • GDPR Articles 4(5), 5(1)(c), 25, 32, Recital 26
  • BDSG Section 22 — German Federal Data Protection Act

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Ready to protect your data?

Start anonymizing PII with 285+ entity types across 48 languages.

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About this page

We update this page when our platform or the law changes.

Read our founder note for how we work.

Each change shows up in the timestamp at the top.

Related reading

We follow these rules

  • GDPR (EU 2016/679).
  • ISO/IEC 27001:2022.
  • NIS2 (EU 2022/2555).
  • HIPAA safe harbor under 45 CFR § 164.514(b)(2).

Our promise

We do not sell your data.

We do not train models on your text.

We store your files in Germany.

You can delete your account at any time.

You own your work.

Where we run

Our servers live in Falkenstein, Germany.

We use Hetzner. They hold ISO 27001 certification.

All data stays in the EU.

Backups run every day.

Need help?

Email support@anonym.legal.

We reply within one business day.

How we test

We run a full check suite on every release.

Each surface gets its own sweep script and report.

Human reviewers spot-check the output each week.

We track recall and precision on a labelled set.

Bad runs block the deploy.

What we never do

  • We never sell your information to third parties.
  • We never train models on what you upload.
  • We never keep your work after you delete it.
  • We never share keys with any outside firm.
  • We never run ads inside the product.

Plans in plain words

We sell credits, not seats.

One credit covers one short job.

Long jobs use a few credits each.

You can top up at any time.

Unused credits roll over each month.

Read the plans page for current rates.

Who built this

A small team of engineers and lawyers built this.

We ship from Europe and work in the open.

Our founder note spells out why we started.

Where to start

How the parts fit

A browser add-on cleans text inside Chrome.

A Word plug-in handles drafts in Office.

A small desktop tool works on whole folders.

An agent protocol link feeds large models safely.

All four share one core engine and one rule set.

Words from our team

We started this work after a lunch about cookies.

One friend kept getting odd ads on her phone.

We asked why a court file leaked through a draft.

We sketched the first build on a napkin that week.

By month three we had a tiny demo for a friend.

She used it on her first case the next day.

Common questions we hear

Can the tool read scanned PDFs? Yes, with OCR.

Does it work on long files? Yes, in small chunks.

Can I roll my own rule set? Yes, save it as a preset.

Does it run offline? The desktop build runs offline.

Do you keep my files? No, the cloud build wipes after each run.

Will it learn from my work? No, we never train on inputs.

A short tour of the workflow

Upload a file or paste a snippet of prose.

Pick the entities you want gone from the draft.

Choose a method: replace, mask, hash, encrypt, or redact.

Press run and watch the side panel show each hit.

Skim the result and tweak any rule that misfired.

Save the cleaned file or send it to a teammate.