A .txt file and a .docx file both contain words, but they are very different things inside. Choosing between them affects compatibility, file size, longevity and how easily you can search, edit and share your work.
Plain text (.txt)
A plain text file contains characters and nothing else: no fonts, sizes, bold, colours, images or page layout. What you type is stored directly as encoded text. Every operating system and thousands of programs can open one, and a plain text file will still be readable decades from now.
- Strengths: universal, tiny, works in every editor, easy to search and compare, ideal for version control, logs, notes and code.
- Limits: no formatting at all, and no way to say how the text should be displayed.
Rich Text Format (.rtf)
RTF is a document format that stores formatting such as bold, italics, fonts, colours, paragraphs and simple embedded images, using control words written in plain ASCII. It was developed by Microsoft in the late 1980s to move formatted text between applications. Most word processors can open and save RTF.
- Strengths: basic formatting with broad compatibility.
- Limits: the format is no longer actively developed, support for modern features is limited and files are larger than plain text. It has largely been replaced by
.docxand.odtfor real documents.
Markdown (.md)
A Markdown file is plain text with conventions for formatting, such as # for headings and ** for bold. The formatting is applied when the file is displayed by a Markdown-aware program, so the file itself stays readable as raw text. See what is a Markdown file and Markdown vs rich text documents.
- Strengths: readable raw, portable, works well with version control, convertible to HTML and PDF.
- Limits: appearance depends on the renderer, and complex layouts are not possible.
Word documents (.docx)
A .docx file is a ZIP archive of XML parts and media that describes text, styles, page layout, images, tables, comments and tracked changes, using the Office Open XML standard. It is a full word-processing format. See DOCX format explained.
- Strengths: rich layout and collaboration features.
- Limits: not human-readable as raw text, and larger, and rendering can differ slightly between applications and versions.
Side-by-side
| .txt | .rtf | .md | .docx | |
|---|---|---|---|---|
| Formatting | None | Basic | Via symbols | Full |
| Readable raw | Yes | Partly | Yes | No |
| Images | No | Limited | By link | Embedded |
| Version-control friendly | Excellent | Poor | Excellent | Poor |
| Typical size | Smallest | Small | Smallest | Larger |
| Long-term readability | Excellent | Good | Excellent | Good |
Choosing
- Notes, logs, code, configuration, data: plain text, or a structured text format such as JSON, CSV or YAML.
- Documentation and writing that will be published to the web or version controlled: Markdown.
- Letters, reports and contracts that need layout, review and comments:
.docx, or PDF for a fixed final version. - Sharing a finished document that must look identical everywhere: PDF.
A common mistake: renaming instead of converting
Renaming report.docx to report.txt does not turn it into plain text; you get a ZIP archive's worth of garbage when you open it. Likewise, saving a word-processor file as .txt strips all formatting, which is irreversible. Use Save As, and keep the original.
Opening text files
Docento's Text & Markdown Editor opens plain text, Markdown and many structured text formats in your browser, with find and download, and without uploading the file. For Word files and PDFs, use a document tool or convert them: see how to convert PDF to text.
Takeaway
Plain text is the most durable and portable format, Markdown adds readable formatting, RTF is a legacy middle ground and DOCX is for full documents. Pick the simplest one that carries what you need.
