Privacy Policy

Yunyu Chengye is provided by Cixi Yunyulai Culture & Technology Co., Ltd. YunyuTrace provides file registration and verification capabilities.

Files stay on your device

Image decoding, screenshot pagination, PDF generation, watermark processing and digest calculation take place locally in your browser. Original images, PDFs, DOCX files, document bodies, chat content and OCR content are not sent to this service. Files and previews from the current task are not retained as cloud history after you close the page.

Information we retain

To support verification, the service stores final file digests, content fingerprints, hashed verification codes, file identity and signature node IDs, page counts, file sizes, generation types, registration times and verification counts. Optional signing after compression also records the relationship between the original and compressed registrations. Full layout manifests and original images are not stored in the database. For automatic verification, external signed evidence packages, page dimensions, salted page commitments, page order and signed page roots are stored in COS. These objects are encrypted on the server and contain no page images. Proof objects are named in association with the exported file name; the database stores hashed verification codes.

Payments and anonymous analytics

Paid exports record the order number, actual order amount, payment status, transaction ID, hashed export authorization and necessary timestamps. Payments are processed by the payment provider. Anonymous analytics record feature events and quantity ranges only. They do not include file content, file names, verification codes or file digests linked to user behavior.

Verification and data retention

Anyone holding a verification code can look up its registration records and compare local file digests to check for changes. Proof is returned only when both the verification code and a matching file digest are provided. The browser automatically compares rendered pages locally. Registration records support future verification; order records support payment reconciliation. You are responsible for saving original and generated files. The service does not offer file recovery or cloud storage.

No account required

No registration, login or phone number is required to use the tools. Each operation is a separate task. Save your files and verification codes before leaving the page.

Language preference

A first-party cookie remembers the interface language for payment return pages. It contains only the language code and expires after one year. It is not used for advertising or cross-site tracking.