DOC vs PDF
A detailed comparison of Word Document (Legacy) and PDF Document — file size, quality, compatibility, and which format to choose for your workflow.
Word Document (Legacy)
Documents & TextDOC is the legacy binary format used by Microsoft Word 97-2003. While superseded by DOCX, many archived and legacy documents still use this format and require conversion for modern editing.
About DOC filesPDF Document
Documents & TextPDF is the universal standard for sharing documents with consistent formatting across all devices and operating systems. It preserves fonts, images, and layout exactly as intended by the author.
About PDF filesStrengths Comparison
DOC Strengths
- Universal compatibility — every Word version since 1997 reads it natively.
- Rich feature set: styles, tables, comments, track changes, embedded OLE objects.
- Binary format means fast loading even on slow machines.
- Well-understood after decades of reverse-engineering — dozens of parsers exist.
PDF Strengths
- Pixel-perfect fidelity across operating systems, browsers, and printers.
- Embeds fonts, so documents render identically without the reader having them installed.
- Supports digital signatures, encryption, and redaction for legal workflows.
- ISO-standardized (ISO 32000) with multiple validated subsets (PDF/A, PDF/X, PDF/UA).
- Supports both vector and raster content, keeping line art crisp at any zoom level.
Limitations
DOC Limitations
- Legacy format — Microsoft stopped improving it in 2007; new features require DOCX.
- Binary structure is fragile; corruption often makes files unrecoverable.
- Historic malware magnet: embedded macros have spread viruses since the 1990s.
- Not open-standard — DOCX is the ISO-standardized successor.
- Subtle formatting drifts when opened in LibreOffice or Google Docs.
PDF Limitations
- Editing is difficult — the format is optimized for display, not mutation.
- Text extraction can scramble reading order in multi-column layouts.
- File sizes balloon quickly when embedding high-resolution images or fonts.
- Accessibility (screen readers) requires careful tagging that many PDFs skip.
- JavaScript support has historically been a malware vector.
Technical Specifications
| Specification | DOC | |
|---|---|---|
| MIME type | application/msword | application/pdf |
| Container | OLE Compound File (Word 97-2003) | — |
| Standard | MS-DOC [MS-OOPR] (released 2008) | — |
| Successor | .docx (2007) | — |
| Character encoding | UTF-16 LE (Word 97+) | — |
| Current version | — | PDF 2.0 (ISO 32000-2:2020) |
| Compression | — | Flate, LZW, JBIG2, JPEG, JPEG 2000 |
| Max file size | — | ~10 GB (practical); 2^31 bytes (theoretical per object) |
| Color models | — | RGB, CMYK, Grayscale, Lab, DeviceN, ICC-based |
| Standard subsets | — | PDF/A, PDF/X, PDF/UA, PDF/E, PDF/VT |
Typical File Sizes
DOC
- Short letter 25-50 KB
- 20-page report 150-400 KB
- Book manuscript with images 2-20 MB
- 1-page text-only memo 50–150 KB
- 10-page report with images 500 KB – 2 MB
- Scanned document (per page) 100 KB – 1 MB
- Full-color magazine (48 pages) 10–40 MB
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Frequently Asked Questions
DOC is the legacy Microsoft Word binary format used from 1983 to 2007, storing text, images, formatting, and embedded objects in the OLE Compound File container since Word 97. It was replaced as default by DOCX in Office 2007 but remains widely used in legacy archives and older government systems.
DOC files open in every Microsoft Word version from 1997 onward, Google Docs (free), LibreOffice Writer (free), Apple Pages, and most online viewers like OneDrive and Dropbox preview. On iPhone and Android, Word apps open DOC natively.
Use KaijuConverter's DOC-to-PDF converter for a single-click conversion. Microsoft Word, Google Docs, and LibreOffice all export to PDF natively via "Save as PDF" or the print menu — the result is identical and preserves every font, layout, and image.
Always DOCX for new documents. DOCX files are 75% smaller thanks to ZIP compression, follow the ISO/IEC 29500 standard, and support every modern Word feature. DOC is essentially a legacy compatibility format — Microsoft stopped improving it in 2007.
Older DOC files could contain VBA macros that became a common malware vector in the 2000s. Modern Office blocks macros by default. If you receive a suspicious .doc, open it in Google Docs or LibreOffice first — both strip macros automatically during import.
Yes. Open the .doc in Microsoft Word and use Save As → Word Document (.docx). LibreOffice Writer offers the same export. Formatting transfers cleanly in 99% of cases; complex features like some legacy form fields may need minor manual fixes.