SignPeek is a fast, privacy-focused web application for instantly previewing digitally signed documents and exploring cryptographic containers directly in your browser. It is designed to make working with signed files simple: drop a file, inspect its contents and signatures, and preview the embedded documents without uploading anything to a server.
✔Digital Signature Support: Works with CAdES binary signatures (`.p7s`, `.p7m`) and XAdES XML signatures.
✔Certificate Analysis: Extracts signer information, organization, certificate authority, and certificate validity data from ASN.1 structures.
✔Container Inspection: Displays signed containers and their embedded files in an interactive hierarchical tree.
✔Recursive Extraction: Handles nested containers and archives, including signed containers stored inside ZIP archives.
✔ASiC Support: Supports ASiC-E and ASiC-S signed containers used by European and Ukrainian electronic signature systems.
✔Smart Export: Download individual files from a container or export the complete container contents as a ZIP archive.
✔Document Preview: Preview PDF, Word (`.docx`), and spreadsheet files (`.xlsx`, `.xls`, `.csv`) directly in the browser.
✔Image Preview: Supports common image formats as well as HEIC and TIFF files.
✔Interactive Viewers: Includes zooming, panning, page rotation, and other viewer controls.
✔Drag & Drop: Quickly open files by dropping them directly into the application.
✔Local Processing: Files are processed entirely in the browser and are not uploaded to a backend server.
✔Responsive Interface: Designed to work across desktop and mobile screen sizes.
✔PWA Support: The application can be installed and used as a Progressive Web App.