Deanonymization (reverse)
Anonymization has a return trip. Once you’ve anonymized a document, sent the safe copy somewhere — an external LLM, a colleague, a tool — and gotten work back on it, deanonymization puts the real values back in. It’s the other half of the round trip.
The point of it
Section titled “The point of it”The whole reason to anonymize before using an external tool is that the tool shouldn’t see real PII. But the answer the tool gives you is about the fake values — it summarizes David Romero Gil, not Marcos Patel. Deanonymization translates that answer back into your real world, swapping the fakes for the originals so the result is usable.
This is what makes Piixie a safe bridge to tools you don’t control: anonymize → use the external tool → deanonymize, with real PII only ever on your machine. The full pattern is in the round-trip workflow.
Two ways back
Section titled “Two ways back”Piixie reverses a document one of two ways, depending on what it has to work from:
- Exact reverse — when the file matches a run in your history, Piixie inverts that run’s stored mappings and applies them backwards. Precise, local, free.
- Dictionary reverse — when there’s no run record (the file was edited elsewhere, or made on another machine), Piixie uses a dictionary of known swaps to find and restore values, tolerating small differences in case and accents.
How you trigger it
Section titled “How you trigger it”- Automatically. When you drop files in, Piixie quietly checks each one against your history. If it recognizes a file as the output of a past run, it asks: “this was anonymized from
…on…— deanonymize it instead?” You can apply your answer to all matched files at once. - Manually. Flip the Deanonymize toggle in the staging area to reverse files instead of anonymizing them. The start button changes to Start deanonymizing.
What it works on
Section titled “What it works on”Text, Markdown, PDF, and Word files — the same formats Piixie anonymizes.
One thing it can’t do
Section titled “One thing it can’t do”Redaction is one-way. If a value was blacked out or replaced with [REDACTED], the original is gone — there’s nothing to restore. Only synthetic and labeled runs are reversible. See limits & safety.