Read first, execute never
HTML, source code, XML, YAML and SVG are displayed as text; they are not executed by OpenMyFile. Known image, audio and video formats use native browser controls. PDF previews rely on browser support.
Signatures and containers
File signatures are matched against known header patterns. ZIP-based containers show central-directory listings; supported Office, EPUB and OpenDocument previews read bounded individual XML parts from those containers without executing content. A signature match is evidence of a likely type, not proof the entire file is valid.
Performance limits
Text/table previews are deliberately limited; archive listings and checksums have bounded sizes. Individual extracted document parts have strict byte limits, and ZIP checksums are verified for supported entries. Larger or proprietary files should be opened in trusted software designed for them.