Confidential document translation: what happens to your deck after you upload it

TL;DR: The risk in translating a confidential deck is not that someone reads it deliberately. It is that the file is retained by default, its contents feed a training corpus, or an output URL turns out to be publicly reachable. Four questions settle it, all four have answers that live in terms of service rather than on landing pages, and most free tools answer at least one of them badly.

The decks that most need translating are frequently the ones you least want to hand over. A board pack before the board has seen it. An unannounced product roadmap for a partner in another market. A restructuring deck for a regional team. Diligence materials for a buyer. Every one of these is a document where the cost of exposure dwarfs the cost of translation, and the upload button offers no way to reason about that.

So reason about it before the upload, with four questions.

What should I ask before uploading a confidential deck?#

Question 2 is the one that has changed most in the last few years, and it is where free tiers are most consistently unsuitable. Consumer-grade services commonly process submitted text under terms permitting use for model improvement. That is a defensible bargain when you are translating a menu. It is not a defensible bargain for a document under NDA, because "used for improvement" is not a thing you can later unwind.

Question 3 is the one people never think of, and the one with the most spectacular precedent. The European Commission's translation knowledge centre records the 2017 incident in which text translated through a free web service was found indexed by Google and retrievable by anyone searching for it — contracts, dismissal letters, internal email. Nobody attacked anything. The outputs were simply reachable, and search engines do what search engines do.

Why is the free tier usually the wrong tool here?#

Because the terms that make it free are the terms that make it unsuitable.

A free service has to pay for itself somehow, and the two common mechanisms are advertising and data. The result is a set of defaults — long or indefinite retention, permissive licensing of submitted content, no data processing agreement — that are fine for the consumer use case the product was designed for and wrong for a document your employer would describe as material non-public information.

This is a procurement judgment, not a moral one. The same company's paid or enterprise tier frequently offers exactly the commitments the free tier withholds: contractual no-retention, no training on customer content, a named subprocessor list. The mistake is assuming the free tier inherits them.

There is a second, quieter version of the same mistake: pasting the deck's text into a chat assistant. It feels less like an upload because no file moves, but the content has still left your perimeter, and the applicable terms are the assistant's consumer terms unless you are on a business plan that says otherwise. The functional limits of that route are in what ChatGPT can and cannot do with a .pptx; the confidentiality limits are separate and generally stricter.

What can you do when the tool is not suitable?#

Three practical routes, in order of how often they are the right answer.

1. Use a tool with written no-retention terms. The straightforward answer, and the one to look for first. "Written" means in the terms of service or a data processing agreement, not in a marketing bullet.
2. Redact before you translate. Replace names, figures and identifiers with placeholders, translate, and restore them locally. Tedious, and genuinely effective for decks where the sensitivity is concentrated in a few cells. Useless for decks where the whole argument is the secret.
3. Keep it in-house or with a contracted human. An agency under NDA, or an on-premise stack. The correct answer for regulated material, and slower and more expensive than everything else, which is precisely why the other two exist.

What does not work is deciding on the basis of how professional the website looks. The four questions have documented answers or they do not.

What does SlideVerso do with your deck?#

Specifics, and only ones the product actually implements.

Your uploaded .pptx is deleted after processing. It is not kept as a corpus, and it is not used to train anything. The translated output is held in private storage and served through signed download links that expire, so there is no public URL for your deck and nothing for a search engine to find — the failure mode from question 3 is closed by construction rather than by policy. Translation runs through the engine that edits the text inside your original file; the deck is processed to produce your output and for no other purpose.

Two things we will not claim, because claiming them would be exactly the kind of assertion this post tells you to distrust. SlideVerso holds no security certification — no SOC 2, no ISO 27001 — and you should not treat it as if it did. And the service is operated under the Golden Corpus brand as a personal operation rather than by a separately incorporated entity, which matters if your procurement process requires a counterparty with a company registration number. If your deck is regulated material, or your compliance function requires a signed data processing agreement with an audited vendor, we are not that vendor and would rather you knew now.

For most business decks — the quarterly review, the partner update, the investor deck for a second market — the four questions have good answers here. For a deck under a regulator's eye, ask them of everyone, including us, and accept only written answers.

Frequently asked questions#

Is it safe to upload a confidential presentation to a translation tool? It depends on four things: whether the file is retained, whether its content is used to train models, whether outputs are ever publicly reachable, and who the subprocessors are. Free consumer services generally answer those badly for confidential business documents, and the answers live in terms of service rather than on landing pages.

Does Google Translate keep the documents you upload? Google's consumer terms grant a broad licence over submitted content, and the free tier is not built around the data-handling commitments confidential business documents require. Treat it as unsuitable for anything under NDA, and read the current terms yourself rather than trusting any third-party summary, including this one.

What should I ask a translation vendor about confidentiality? How long is my input file stored and when is it deleted? Is my content used to train or improve any model? Can the output be reached by anyone without my link or login? Which third parties process my text, and where? A vendor that cannot answer all four in writing has answered the first question.

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If those answers work for your deck, the rest is quick: upload a .pptx, get one watermarked slide back free, and see the exact per-deck price before you pay anything. Translate a deck. What survives the process, technically, is covered in everything that breaks when you translate a deck.