Every tool on this site works with plain text. When you paste formatted content from Word or Google Docs into the word counter or case converter, the formatting is stripped automatically. You get back clean text without fonts, colours, or sizes. This is by design, and understanding why requires knowing the difference between plain text and rich text at a technical level.
What Plain Text Actually Is
Plain text is a sequence of characters with no formatting metadata. A plain text file contains only the characters you can see: letters, numbers, punctuation, spaces, and line breaks. Open a .txt file in any text editor on any operating system and it displays the same content. There is no font information, no bold or italic markers, no colour data, and no layout instructions. The file is just characters encoded in a format like UTF-8 or ASCII.
This simplicity is the reason plain text has survived for decades while dozens of rich text formats have come and gone. A plain text file created on a 1980s computer is still readable today. Try opening a WordPerfect 5.1 document from the same era and you will need specialised software or a converter. Plain text is the universal format that every system on earth can read.
Common plain text file extensions include .txt, .csv, .md (Markdown), .html (before rendering), .css, .js, and most programming language source files. All code is plain text. Configuration files are plain text. Log files are plain text. The digital world runs on plain text even though most users interact with rich text in their daily work.
What Rich Text Adds
Rich text embeds formatting instructions alongside the content. A bold word in rich text is not just the word itself but the word plus hidden markers that tell the rendering application to display it in bold. Different rich text formats use different methods for these markers. HTML uses tags like <strong>. RTF uses control codes like \b. DOCX uses XML structures inside a ZIP archive.
The formatting information in rich text includes font family, size, weight, colour, alignment, spacing, margins, headers, footers, embedded images, tables, and page layout. A Word document is not just text. It is a complex package of content, formatting instructions, metadata, and embedded assets. This is why a .docx file for a one-page letter can be 50 kilobytes while a plain text file with the same words is 2 kilobytes.
Rich text formats are application-specific to varying degrees. DOCX is designed for Microsoft Word. Pages uses its own format. Google Docs uses an internal format that only Google's application can natively edit. While cross-application compatibility has improved, subtle formatting differences between applications remain a source of frustration for anyone who has opened a Word document in Google Docs and found the layout shifted.
When to Use Plain Text
Use plain text when the content needs to work across different systems, when formatting would be stripped anyway, or when the raw content is what matters. Email is a good example. HTML emails with rich formatting look different in every email client and get mangled by forwarding and replying. Plain text emails look the same everywhere and survive any amount of forwarding intact.
Data interchange should always use plain text formats. CSV files for tabular data. JSON or XML for structured data. Markdown for formatted content that needs to render in multiple contexts. These formats are human-readable, version-controllable, and compatible with every tool in the chain. I use plain text for all data cleaning workflows, which is why the tools on this site process plain text rather than formatted documents.
Code and configuration files must be plain text. Any formatting metadata would be interpreted as part of the code and cause errors. This is why pasting code from a word processor into a terminal or code editor often fails. The invisible formatting characters that come along break the syntax.
Note-taking works well in plain text, especially with Markdown for lightweight formatting. I switched from Notion to plain Markdown files a couple of years ago and the portability has been worth the trade-off. My notes work in any editor, sync with any service, and will be readable in 20 years regardless of what happens to any particular application.
When to Use Rich Text
Rich text is the right choice when visual presentation matters and the document will be consumed in a specific context. Business reports, printed documents, presentations, and marketing materials need formatting to communicate effectively. A resume needs careful typography. A contract needs numbered clauses and indentation. A brochure needs colour and layout. Plain text cannot serve these purposes.
Collaborative writing in organisations typically requires rich text because people need to see formatting as they write, track changes visually, and produce polished output directly from the editor. Google Docs and Word exist because rich text editing in a shared environment solves a real problem that plain text does not address.
Converting Between Formats
Converting rich text to plain text is lossy. You lose all formatting. Bold text becomes regular text. Headings become regular paragraphs. Tables lose their structure. This is why pasting formatted content into the tools on this site gives you clean text. The browser's paste handler strips the formatting automatically.
Converting plain text to rich text is additive. You start with the raw content and add formatting on top. Markdown is the most popular bridge between the two worlds. It uses plain text characters like asterisks and hash symbols to indicate formatting, which rendering engines then convert to rich visual output. This document was written in a system that uses a similar approach: structured plain text that gets rendered as a formatted web page.
The practical takeaway is to write and store content in the simplest format that meets your needs. Start with plain text. Add formatting only when the output genuinely requires it. This approach gives you maximum flexibility because plain text can always be formatted later, but stripping formatting from rich text loses information that cannot be recovered.