OnePreview

Preview Markdown and developer files instantly with Apple Quick Look on iPhone, iPad, and Mac. OnePreview renders GitHub-style Markdown, MDX, TextBundle and TextPack packages, JSON, JSONL, YAML, XML, CSV, TSV, TOML, ENV, SQLite databases, source code, plain text, logs, folders, and ZIP archives. Open a file from Files or Finder and understand it without launching a full editor. Switch between rendered Markdown and source, view Mermaid diagrams and KaTeX math with bundled assets, inspect structured data and SQLite schemas, browse folders, and check ZIP contents before extracting. Built for developer workflows, AI-generated files, documentation review, and everyday file browsing. Previews are fast, local-first, and integrated into the system preview flow.