Guide
Tools to anonymise client documents before ChatGPT or Claude: 2026 comparison
By Hugo Ribeiro · Updated
| Tool | Type | Local or cloud | Reversible | Files | Published price |
|---|---|---|---|---|---|
| Velado | Desktop + browser app | Local | Yes, automatic | Word, Excel, PDF (OCR), SAF-T, e-invoices, CSV | €129/year or €14/month; beta free until 31 Jan 2027 |
| Nonimo | Mac/Windows app + extension | Local | Yes | Text, Word, Excel, PowerPoint, PDF, OpenDocument | Free until 15 Jan 2027; paid plans not yet published |
| anonym.legal | Web, Office add-in, extension, desktop app | Cloud (Germany); desktop app described as offline | Yes | Word, Excel, PowerPoint, text | €0 / €3 / €15 / €29 per month |
| CamoText | Desktop app | Offline | De-anonymisation options (Pro) | Not detailed | $59 or $79 lifetime |
| Caviard | Chrome extension | Local | Partial (toggle) | Text typed in ChatGPT / DeepSeek | Free tier |
| Priversi | Web tool | Local in the browser | Yes (paste the answer back) | DOCX, PPTX, XLSX, PDF | Free |
| Presidio | Open-source SDK | Local / self-hosted | With encrypt/decrypt or custom code | Text, images, structured data | Free |
| OpenAI Privacy Filter | Open model | Local | No | Text | Free (Apache 2.0) |
| Adobe Acrobat Pro (Redact) | PDF editor | Local | No | €24.59/month (annual plan, PT, VAT incl.) | |
| Business AI (ChatGPT Business, Claude Team, Copilot) | AI service | Cloud: receives the data | Not applicable | Whatever you upload | ≈ $20–30 per user/month |
Checked on each vendor's pages on 9 November 2026, except Caviard (Chrome Web Store) and Priversi. Features and prices change: check before you buy. Velado is our product.
How to choose
- Only text in a chat window? An extension is enough. Check whether it really runs locally and whether it can restore the answer.
- Office files and PDFs? You need a tool that opens and rewrites the file itself, including hidden sheets and comments.
- Professional secrecy? Prefer local processing. A cloud anonymiser is still a third party receiving the original.
- Your country's identifiers? Generic tools catch names and emails well; tax and ID numbers vary by country and need specific, validated patterns.
- Reversibility. For AI work you want the real names back in the answer. Redaction tools can't do that.
Where Velado fits
Velado was built in Lisbon by a certified accountant for professions bound by secrecy. It is the only tool in this list with SAF-T support and checksum validation for Portuguese, Spanish and Brazilian tax IDs, and it covers UK, Irish, US, Canadian, French and Maltese identifiers too. See also Velado vs Presidio, Velado vs manual redaction and the comparison with business AI plans.
FAQ
Is a business AI plan enough on its own?
It protects your data by contract and usually doesn't train on it, but the provider still receives the documents with client identities. A local anonymiser means it receives codes instead.
Are free tools safe?
Several are local and genuinely useful. Check where processing happens, whether the mapping is stored securely and whether the tool handles your files and your country's identifiers.
Read next
Velado vs. ChatGPT Business, Adobe Acrobat and manual redaction: which keeps client data private?
ComparisonVelado vs Presidio: open-source SDK or ready-made app for removing client data before AI?
ComparisonVelado vs manual redaction in Word or Acrobat: what gets missed and why the AI loses context
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