The difference in one sentence
Markdown is editable plain text with formatting markers; PDF is a document format that preserves a page layout. Keep Markdown when you will keep working on the content. Send PDF when the reader needs the arranged pages.
| Task | Markdown (.md) | PDF (.pdf) |
|---|---|---|
| Edit and reuse text | Open and edit in any text editor; headings and code remain text. | Text can be edited with suitable software, but page layout makes substantial revision less convenient. |
| Read, share and print | Appearance depends on the app and its theme; no fixed page breaks. | Keeps page dimensions and layout; opens in browsers and PDF readers. |
| Track changes in Git | Line-by-line text differences are easy to inspect. | Ordinary text diffs are not useful for the file; compare rendered pages or extracted text. |
| Code and formulas | Code stays reusable. Math syntax needs a compatible renderer. | Shows the rendered result, but it is less convenient to recover the original formula source. |
| Images | Usually references images by path or URL; keep local assets with the file. | Can embed images in the document; verify the export actually included them. |
| Comments and review | Use editor comments, repository reviews or a linked discussion. | Many PDF readers support annotations. For tracked text revisions, DOCX is often a better handoff. |
Choose by what happens after saving
For an Obsidian note, README or research draft, choose Markdown. You can revise a paragraph or copy a code block without rebuilding a page layout. A text-only file is usually small, although an accompanying image folder can be much larger.
For a report someone will read or print, choose PDF. Check wide tables and long code lines before sending it. PDF is not inherently read-only, tamper-proof or compliant with a record-retention rule; those requirements depend on the document and your process.
A practical workflow: Markdown source, PDF handoff
Keep project-notes.md while editing, with its image folder beside it. Create project-notes.pdf when you need to send a reviewed version. If you change the source later, regenerate the PDF so the two copies do not disagree.
Converting Markdown to PDF requires a renderer to choose fonts, margins and page breaks. Converting a PDF back to Markdown can lose table structure, reading order or formula source. Keep the original Markdown if you expect more revisions.
For ChatGPT conversations
ChatShell can export the current conversation directly to PDF or Markdown. PDF generation runs in the browser and may fetch fonts. Markdown keeps text for your notes app; use its image option when you also need downloadable images, and keep the downloaded assets together.
Pro batch export supports HTML, Markdown, DOCX and JSON, but not PDF. Choose DOCX for editing in Word, or JSON for structured processing. A JSON export does not automatically restore chats into another service.