At work, one organization asks for HWP, another for DOCX and another for PDF, all for the same content. Knowing what each file type is good for helps you choose the right format and decide how to open what you receive.
Word processor documents
HWP
The default format of Hancom's Hangul word processor. It has long been a de facto standard in Korean public institutions, schools and research organizations. Its internal structure is binary, which makes it hard for other programs to reproduce perfectly. See the HWP Viewer to open it without installing anything.
HWPX
Hangul's open, XML-based format, following the OWPML specification adopted as the Korean national standard KS X 6101. Like DOCX, it is a ZIP archive containing XML files. Its use is growing, especially in the public sector.
DOCX and DOC
Microsoft Word formats. DOCX (Word 2007 and later) is a ZIP-and-XML format based on the international OOXML standard, while DOC (Word 97-2003) is the older binary format. They are common in international business, foreign companies and universities.
Fixed-layout documents
A format designed to "look the same wherever it is opened". Fonts and images can be embedded in the file, which makes it the best choice for submitting, distributing and archiving. It is hard to edit, so think of it as a final version format.
Spreadsheets and data
XLSX and XLS
Excel formats. XLSX is ZIP and XML, while XLS is the older binary format. They can hold formulas, formatting, multiple sheets and charts.
CSV
Plain text with values separated by commas. No formatting or formulas, but almost every program can read it, which makes it ideal for exchanging data. Watch out for broken Korean text caused by encoding differences.
Presentations
PPTX
PowerPoint's Office Open XML format for slides. The PPT Viewer shows it slide by slide, with a slideshow mode.
Text documents
TXT
Plain text with no formatting at all. It is light and opens anywhere, but Korean text breaks if the encoding (UTF-8 or EUC-KR) does not match.
MD (Markdown)
A text format that marks headings, lists and emphasis with simple symbols like "#", "-" and "**". It is widely used for developer documentation, note apps and AI chatbot answers. Open it nicely formatted with the Markdown Viewer.
Which format to choose
| Situation | Recommended format | Why |
|---|---|---|
| Final submission of an application or report | The layout is fixed and does not break | |
| Filling in a Korean public-sector form | HWP or HWPX | The official templates are made in Hangul |
| Co-editing with international partners | DOCX | The global word processor standard |
| Exchanging data | CSV or XLSX | Easy to reuse in other programs |
| Development and automation | CSV or JSON | Easy for programs to read |
| Quick notes | TXT or MD | Light and opens anywhere |
When a file will not open
- Make sure file extensions are not hidden (File Explorer > View > File name extensions).
- Use a viewer that matches the extension. InstantDocView opens HWP, HWPX, DOCX, PPTX, XLSX, CSV, PDF, TXT and MD on one page.
- If it still fails, the file may be damaged or password-protected, so ask the sender for a PDF.