How to open a .CMP file online
No extra software to download or install.
Pick your .CMP file
Drag it in or click to choose it. We read its contents list first, so it opens right away without unpacking everything.
Browse what's inside
See every file with its size, how much it's compressed and its date, and search by name across all the folders.
Preview or download
Click a file to preview text or images, or save just that one. Need everything? Download it all as a single ZIP.
About .CMP files
What a .CMP file is, and what's inside it.
A .cmp file is most often a raw PKWARE DCL (Data Compression Library) compressed stream, but the extension is also used for JEDMICS C4 scanned images, Yamaha keyboard data, and CAD color-map files. There is no universal opener. The right tool depends on which program created the file, so inspect the file in a hex editor first.
Programs that open .CMP files
| Full name | PKWARE Data Compression Library archive |
|---|---|
| Developer | PKWARE, Inc. |
| First released | 1990s (PKWARE Data Compression Library, DCL) |
| Category | Archives |
| MIME type | application/octet-stream |
Related viewers
Found something inside the archive? Open it here.
Do I have to unpack the whole .CMP file?
No. The viewer reads its table of contents first and only unpacks a file when you click it. That works even with multi-gigabyte archives, because we read just the bytes we need.
Can I open password-protected archives?
Yes, for ZIP (ZipCrypto and AES) and 7Z. You'll be asked for the password,. We can't recover forgotten passwords.
Is my .CMP file uploaded anywhere?
No. The code that unpacks the file is downloaded once and then reused.
Why does a .docx or .apk open as an archive?
Because they are ZIP archives under the hood. Office documents, Android apps, Java programs and EPUB books all use ZIP as their container.
What about split archives (.001, .z01, .part1.rar)?
Multi-part archives need all their parts. Today you can open the first part to see the file list; joining parts is on our roadmap.
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