📄 Document File Extensions
Complete guides to open, edit, and convert document files including PDF, Word, Excel, PowerPoint, and more. Free tools for every platform.
Most Popular Document Formats
Portable Document Format
Universal document format for sharing. Preserves formatting across all devices and platforms.
Opens with: Adobe Reader, browsers, Preview
Open PDF Files →Microsoft Word Document
Standard word processing format. Used for letters, reports, resumes, and professional documents.
Opens with: Word, Google Docs, LibreOffice
Open DOCX Files →Microsoft Excel Spreadsheet
Spreadsheet format for data analysis, calculations, charts, and financial modeling.
Opens with: Excel, Google Sheets, LibreOffice
Open XLSX Files →PowerPoint Presentation
Presentation format with slides, animations, and speaker notes for business and education.
Opens with: PowerPoint, Google Slides, Keynote
Open PPTX Files →Legacy Word Document
Older Word format (1997-2007). Still widely used in archives and older systems.
Opens with: Word, Google Docs, LibreOffice
Open DOC Files →Plain Text File
Simple text without formatting. Universal compatibility across all systems.
Opens with: Notepad, any text editor
Open TXT Files →Document Formats by Category
📝 Word Processing
Text documents with formatting
📊 Spreadsheets
Data, calculations, and charts
📽️ Presentations
Slides for business and education
📕 PDF & eBooks
Fixed-layout documents and books
🔧 Data & Config
Structured data files
How to Open Document Files
Most document files can be opened with free software. Here are the best options for each platform:
Windows
- Microsoft Office - Best compatibility for DOCX, XLSX, PPTX
- LibreOffice - Free, open-source alternative that opens all formats
- Adobe Acrobat Reader - Free PDF viewer
Mac
- Pages, Numbers, Keynote - Free Apple apps for documents
- Preview - Built-in PDF viewer
- Microsoft Office for Mac - Full compatibility
Online (Free)
- Google Docs/Sheets/Slides - Free, works in any browser
- Microsoft 365 Online - Free web versions of Office apps
Mobile
- Microsoft Office apps - Free on iOS and Android
- Google Docs apps - Free, syncs with Drive
Document Format Comparison
| Format | Best For | Editable | Free Software |
|---|---|---|---|
| Sharing final documents | Limited | Adobe Reader, browsers | |
| DOCX | Writing and editing | Yes | Google Docs, LibreOffice |
| XLSX | Data and calculations | Yes | Google Sheets, LibreOffice |
| TXT | Simple text, code | Yes | Notepad, any editor |
| CSV | Data exchange | Yes | Any spreadsheet app |
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