Paret Labs · MuteDoc
Stop sending confidential data to AI tools (Claude, ChatGPT, etc.)
MuteDoc finds the confidential data in a document, names, addresses, emails, phone numbers, IBANs, national insurance numbers, replaces it with labels, and gives you the original text back when you are done. Everything happens on your machine: no data leaves it, there is no account to create and no server to call.
Mrs Perpetua Wobblesworth, born 5 May 1905, residing at 14 Marmalade Lane, Pemberton-under-Cloud, ZZ9 9ZZ, reachable on +44 7700 900123 or at p.wobblesworth@example.com. Against PLUMES AND ANVILS LTD, represented by its manager Barnaby Turnstile. Payment received on account FR76 0000 0000 0000 0000 0000 000.
The text is genuinely replaced, not covered: copying the protected document yields the labels only.
The trial covers 5 complete documents, with no time limit, no credit card and no sign-up. We send the installation link and the file fingerprint by email.
Sending a document to an AI means handing it to a third party.
Submitting a working document to an artificial intelligence service means transmitting it to someone else. That implies a processing agreement under Article 28 GDPR, an assessment of transfers outside the European Union, an entry in the record of processing activities. And for anyone bound by professional secrecy, be they lawyers, doctors, notaries or accountants, those three pieces leave untouched the question that actually exposes them: under Article 226-13 of the French Criminal Code, disclosing privileged information to a third party carries one year's imprisonment and a €15,000 fine. It falls on the person who holds the secret, not on the firm, and no agreement signed with the AI provider releases them from it.
Most anonymisation tools upload your document in order to mask it, so they add a processor, whereas MuteDoc is desktop software that works on your machine without opening a single outbound connection: no processor, therefore no transfer.
| Three ways to handle the same file | MuteDoc | Online anonymisation service | Redacting by hand |
|---|---|---|---|
| Where the document goes | Nowhere. It stays on the machine. | To the provider's servers. | Nowhere. |
| Processor to declare | None. | One, with an Article 28 agreement and a transfer assessment. | None. |
| Getting the real names back | Yes, from an encrypted vault only you can open. | Varies, and the table sits with the provider. | By hand, line by line. |
| Time for a ten-page file | Seconds, then your review. | Seconds, plus the upload. | Half an hour, and one slip gets through. |
| Cost | €149 once, per user. | A subscription, per user per month. | Your time, on every file. |
Wherever a case file carries identities.
The engine knows nothing about professions: it knows names, addresses, national insurance numbers, IBANs, company registration numbers. And whatever it does not recognise, you point out to it: a matter name, a client's name, a project title, any term you consider confidential is masked like the rest. Anywhere a working document carries identities and you would like to lean on an AI without handing them over.
Masking the confidential data in a document, in four steps.
You open the document
Plain text, Word or PDF. The software picks up names of people and organisations, addresses, emails, phone numbers, IBANs and payment cards, national insurance numbers, company registration numbers, dates of birth, number plates, web and IP addresses, plus any term you add yourself.
You review the detections
Every detection is shown in context. You dismiss one, add another, change a label. Your review is what counts, not ours.
You export
The masked document comes out as text, Word or PDF. In all three formats the original name is replaced in the text itself: it survives nowhere in the file produced. On a PDF the page is rebuilt, not covered with a black box that leaves the text underneath selectable.
You get the identities back
The mapping table is stored in a vault encrypted with your passphrase (scrypt and AES-256-GCM). It lets you put the real names back into the answer the AI returned. You can also choose not to keep it at all.
What never leaves your machine.
That is the number that matters in a compliance file. No Article 28 agreement with us, no transfer assessment, no processor to enter in your record of processing activities: there is nobody to declare for a document that never left.
The figure covers MuteDoc, and MuteDoc alone. It says nothing about the AI service you then send the masked document to: that one remains your processor, with its agreement, its transfer assessment and its record entry, because a pseudonymised document is still personal data under Article 4(5) GDPR. What MuteDoc changes is what you hand over.
The “Copy” button on re-identified text puts the real identities into the system clipboard. Windows keeps a history of it, synchronised to its servers when the option is on; macOS does the same through Handoff. That path is outside the application. For sensitive material, save to a file instead, or turn off your system's clipboard history.
The mechanisms, and how to check them yourself, are on the Security page (in French).
“Anonymising” confidential text: the word is wrong, and it matters.
The software assists the detection of personal data. It guarantees neither the completeness nor the accuracy of that detection. Checking the document produced is the user's responsibility before any transmission to a third party.
This is not boilerplate, and we put it here rather than at the bottom of a terms page. Detection is rule-based; an entity can be missed, particularly an unusual name, a nickname, or an identity that follows from context without being written down. The review step is not a formality: yours is what protects the file.
We speak of pseudonymisation. As long as the mapping table exists, the masked document remains personal data within the meaning of Article 4(5) GDPR. The “single block” mode removes reversal by the tool, but a case file often stays re-identifiable by cross-referencing: so we never write that anonymity has been achieved.
One licence per person, once, for good.
Free
5 complete documents
- Every function unlocked
- No credit card, no sign-up
from149 €
Per named user, VAT not applicable
- One licence per person who uses it
- No expiry, security fixes for five years
From six licences on, the unit price goes down: ask for a quote and we come back with the figure for your volume. Sold to businesses and legal entities only. The rest is in the terms of sale and the licence agreement, both in French.
Watch it work on your own files.
Tell us who you are and which system you work on: we send the installation link, the file fingerprint to check it with, and how to proceed. Windows and macOS are both available.
Request received. We will email you the installation link and the file fingerprint.
What we are asked most often.
How do you anonymise confidential text before sending it to an AI?
You open the document in MuteDoc, you review the detections it proposes, you point out the terms it could not have guessed, then you export the masked version: that is what you hand to the AI. Everything happens on your machine, with no account to create and no outbound connection.
One word on the verb, because it matters to a DPO: this pseudonymises, it does not anonymise. As long as the mapping table exists, the masked document remains personal data under Article 4(5) GDPR. What you gain is not anonymity, it is no longer handing identities to a third party.
Does MuteDoc really anonymise my documents?
No, and we never claim it does: MuteDoc pseudonymises within the meaning of Article 4(5) GDPR. As long as the mapping table exists, the masked document remains personal data. The “single block” mode removes reversal by the tool, but a case file often stays re-identifiable by cross-referencing. That is the distinction your DPO will ask about, and the one we hold to.
Are my documents sent anywhere?
No. Processing is entirely local and the application opens no outbound connection. You can check it with a network analyser, and it is the whole point of the product.
Which systems does it run on?
Windows and macOS, both available. On macOS an Apple Silicon Mac (M1 and later) is required; Intel Macs are not supported.
Why is there no download button?
Because software that handles material covered by professional secrecy is handed over in person. You request a trial, we send the link and the SHA-256 fingerprint of the file: you know who what you are installing came from, and you can check it before opening it.
What happens if I lose my passphrase?
The vault becomes unreadable, permanently. There is no recovery: we hold nothing that would let us work around it. The masked document stays usable; only the return to real identities is lost.
Does the licence expire?
No. It has no term and verifies offline, without calling any server. We provide security fixes for five years from purchase, and feature updates for twelve months. Beyond that the installed version keeps working indefinitely.
How many licences do I need?
One per person who uses it. Each licence covers two workstations belonging to that same person, typically a desktop and a laptop, provided they are not used at the same time.
The key is bound to the hardware fingerprint of the workstation, computed on the machine itself: the limit is real without any server counting anything, and without the software opening a single connection.
Someone leaves, someone joins, a machine dies: you write to us, we send a new key, free of charge and without asking for a justification. We count nothing remotely and we do not audit your estate.
MuteDoc is published by Paret Labs.
Paret Labs is an AI and digital transformation agency: we spend time inside our clients' work, we write copilots, custom AI agents and business software ourselves, and we support teams through to adoption.
MuteDoc is the software we publish. Its shape follows from what it has to guarantee: desktop software, no account, no server. An online subscription would have been easier to sell, and would have destroyed the point of the product.
Another AI project in your teams?
We also build copilots, agents and custom business software. A 30-minute call: you describe a team and its friction, we tell you what we would do there and what it could return.
Talk to Paret Labs