Document
What is a .chi file?
A .chi file is a ChiWriter Document (version 3). This is a document format, so it holds text and layout meant to be read. Confusingly, this extension has been used by 2 different formats over the years — they're all listed below.
This extension has been used by more than one format
2 different formats have claimed .chi over the years, so two files with the same extension aren't necessarily the same kind of thing.
How to open a .chi file
- Try LibreOffice (free, Windows/Mac/Linux) — it opens an enormous range of current and historic document formats.
- Microsoft Word and Google Docs handle most mainstream document types.
- If nothing opens it, open it in a text editor: many older document formats have readable text inside.
The registry records this extension against ChiWriter Document, ChiWriter Document, so software from that family is the most likely match.
How to convert a .chi file
- Once it opens in LibreOffice or Word, Save As .docx or .pdf to get it into a format you can use anywhere.
The technical record
For archivists, developers and the merely curious: these are the PRONOM registry entries for .chi.
| Format name | Version | MIME type | PUID |
|---|---|---|---|
| ChiWriter Document | 3 | — | x-fmt/309 |
| ChiWriter Document | 4 | — | fmt/300 |