The WPD file (.wpd)

A .wpd file is a document saved by WordPerfect. Bruce Bastian and Alan Ashton wrote the first version in 1979 for a minicomputer in Orem, Utah, and their company, Satellite Software International, sold it as SSI*WP from 1980. Under the WordPerfect name it became the standard word processor on DOS: WordPerfect 5.1 for DOS, released in November 1989, was its most successful version.

Microsoft Word overtook it in the Windows years. Novell bought WordPerfect in 1994 for $1.4 billion and sold it to Corel in 1996 for $186 million. Corel still sells WordPerfect Office for Windows; its most recent major version is WordPerfect Office 2021. There's no current version for the Mac.

WordPerfect never disappeared from law firms and government offices, which valued its macros and Reveal Codes. Corel's Professional edition includes a legal toolbar for pleading papers and tables of authorities. So WPD files still turn up in court records, contracts and archives.

• It's binary. Open one in a text editor and you'll see the words between unreadable bytes.
• It's one stream of text and codes. Bold, fonts, margins and tabs are codes placed in the text where they take effect, not styles kept somewhere else.
• It's stable. The format has barely changed since WordPerfect 6 in 1993, so a file from the 1990s and one from WordPerfect Office 2021 share the same structure.

WordPerfect's best-known feature is Reveal Codes: a second pane under the document that shows every formatting code as a small named token between the words. Turn on bold and a Bold On code appears before the text and a Bold Off code after it. Change the margins and a margin code appears at that point, affecting everything after it. You can select a code and delete it like a letter.

That pane is close to a picture of the file. A WPD document is a sequence of characters with codes mixed in, in the order you see them in Reveal Codes. Word works differently: a DOCX holds paragraphs and runs of text, each carrying its formatting as properties, so there's no code to find and delete.

This difference is the root of most conversion trouble: codes that apply from one point onwards have to be turned into properties on each paragraph, and a stray code becomes formatting that's hard to trace in Word.

Since version 6, WordPerfect has avoided changing the format, so that offices didn't need to keep old versions around to exchange files. WordPerfect X5 documents are fully compatible with WordPerfect 6.0a documents in both directions, and WordPerfect 5.1+ for DOS was released so that older DOS PCs could use the WordPerfect 6 format.

If you need to keep a WordPerfect document readable for the long term or send it to people without WordPerfect, convert it: to DOCX or ODT to keep editing it, or to PDF to keep it as it looks.

• WordPerfect Office (Windows 10 and 11) opens WPD files and can save a document as WPD, PDF and HTML at the same time. It also opens and saves Microsoft Office formats, so File, Save As, Word document is the cleanest conversion.
• LibreOffice Writer (free, Windows, macOS, Linux) imports WordPerfect files through libwpd, which reads WordPerfect 4 to 11 for DOS and Windows and WordPerfect for Macintosh 1.x, 2.x and 3.5e. Later versions use the same format. LibreOffice can't save as WPD; save as DOCX, ODT or PDF.
• On a server: soffice --headless --convert-to docx letter.wpd or --convert-to pdf. For text only, the wpd2text tool from libwpd prints the words.
• Microsoft Word can open WordPerfect files when a WordPerfect converter is installed, but it can't save them as WordPerfect.
• On a Mac, phone or tablet: there's no WordPerfect. Use LibreOffice on a Mac, or ask the sender for a DOCX or PDF.
• In a browser: browsers can't display WPD files, so a link to one downloads it.

• Windows doesn't know what to open it with. Without WordPerfect installed, nothing is registered for .wpd. Install LibreOffice and open the file from inside it.
• Formatting shifts after conversion. Codes that apply from one point onwards become paragraph properties, and fonts the document asks for may be missing. Compare the result with the original, or with a PDF made by WordPerfect.
• Accented letters or symbols come out wrong. WordPerfect stores many characters in its own character sets, which a converter has to map to Unicode. Rare symbols may be missing from the mapping.
• A password prompt, or nothing readable. The header's encryption field is set. You need the password, or ask the author for an unprotected copy.
• An old file without an extension. If its first bytes are FF 57 50 43, it's WordPerfect: add .wpd and open it in LibreOffice or WordPerfect.

WPD files are rarely used for attacks today, but a few things are worth knowing:

• Document summary. The prefix packets can hold the author, subject, keywords, account, address and dates. Check the document's properties before you send it outside your organisation.
• Comments travel in the text. A comment is a code in the text stream. It's hidden on the page but still in the file, and converters may carry it into the DOCX.
• Parsers. The format is old, complex and mostly read by reverse-engineered code. Keep LibreOffice and other readers up to date, and treat files from unknown senders with care, as with any document.