Occulta is a document anonymization tool designed for professionals who need to use large language models (LLMs) like ChatGPT, Claude, Mistral, or Gemini while complying with professional secrecy obligations (Article 66-5) and the General Data Protection Regulation (GDPR). The application automatically detects and replaces sensitive information within documents before they are sent to an AI service. Detected data types include names, addresses, amounts, case numbers, IBANs, NIR numbers, SIREN/SIRET identifiers, and company forms, with detection calibrated for French formats. After the AI processes the anonymized text, Occulta reintegrates the original values into the response, ensuring the user receives a complete and readable result while the underlying data never leaves their environment in plain text. The workflow operates in three stages. First, the user pastes a document or keeps a provided example. Second, Occulta scans the text and displays a preview of what will be masked, allowing the user to review and override any false positives before anything is sent. Third, the user validates the anonymized text, which is then sent to the chosen AI model. The mapping table linking tokens to original values remains on the user's machine and is never transmitted. Each processing event is logged by type and token only, without storing the actual values, to support compliance documentation. Occulta offers tiered subscription plans. The free tier includes 5 documents per month with masking and response restoration, French data detection, human review before sending, and an audit log. The Pro plan provides 100 documents per month, file import support (PDF, Word, ODT, Excel, CSV), choice of AI engine (Claude, Mistral, or Gemini), a personal glossary, and PDF export of the audit log. The Team plan includes 500 documents per month with shared resources, 5 users included with additional users available, a shared cabinet glossary, an administration console, and direct support via video or phone. The tool is accessed through a web browser and includes a free demonstration that runs locally without sending data.