Why Won't My RAR File Open? Common Errors and Fixes

Start with the error you're seeing, then work down the list.

Match the Error to the Cause

Wording varies between apps; 7-Zip often says "Cannot open file as archive" where WinRAR says the format is unknown.

1. The Download Is Incomplete

This is the most common cause by a wide margin. A dropped connection, a browser that "finished" early or a sync app that hadn't finished uploading all leave you with a file that ends mid-stream. Extractors notice when the data runs out and report unexpected end of archive.

How to check:

• Compare the file size with the size shown on the download page or by the sender.
• Look for .crdownload, .part or .tmp leftovers in your downloads folder.
• If you can, ask for a checksum (MD5 or SHA-256) and compare it.

The fix is simply a fresh, complete download. Nothing can recover data that never arrived.

2. It's Part of a Multi-Volume Archive

Large archives are often split into numbered parts: film.part1.rar, film.part2.rar and so on, or the older film.rar, film.r00, film.r01 scheme. Each part on its own is useless. Opening a later part produces errors about previous volumes; a missing middle part stops extraction partway through.

To fix it:

1. Download every part into one folder, without renaming any of them.
2. Open the first part (.part1.rar or the plain .rar in the old scheme).
3. The extractor will continue through the others automatically.

Online RAR openers, including ours, generally accept a single archive file, so multi-volume sets are best handled by a desktop extractor.

3. The Password Is Wrong

Encrypted archives fail with password or checksum errors when the password doesn't match. Remember that passwords are case-sensitive and that pasted passwords often carry an invisible trailing space. Our guide to password-protected RAR files walks through every cause of a "correct" password being rejected.

4. The Archive Is Corrupted

A CRC failed message means the extractor decompressed a file and its checksum didn't match the one stored when the archive was created. Something changed the data: a faulty disk, a bad USB stick, a transfer error, or the archive was already broken when it was made.

What you can do:

• Re-download or re-copy the file. If the source is fine, a fresh copy fixes it.
• Repair it with WinRAR, if the archive has a recovery record. WinRAR's Repair archive command uses that extra data to rebuild damaged sections. Without a recovery record, repair can only salvage intact files.
• Extract what you can. Many extractors let you keep broken files, which is sometimes enough for text files or videos where a small glitch is acceptable.

Solid archives are more fragile here: damage early in the stream can affect every file after it. What a RAR file is explains why.

5. It's Not Actually a RAR File

A file extension is just part of a name. Downloads are sometimes ZIP or 7z files that were renamed, HTML error pages saved with a .rar name, or, worse, executables disguised as archives.

Every RAR file starts with the bytes 52 61 72 21 1A 07, the ASCII text Rar! followed by two control bytes. RAR5 archives continue with 01 00; RAR4 with 00. You can check the first bytes with a hex viewer, which will also identify the real format from its signature. If the file starts with <!DOCTYPE html> or <html, you downloaded a web page, not an archive.

If the file is actually a 7z or ZIP, just open it with the right tool.

6. Your Extractor Is Too Old

RAR5 has been WinRAR's default format since 2013, but some old extractors and abandoned phone apps only understand RAR4. The symptoms are "unsupported" or "unknown method" messages on an archive that opens fine elsewhere. Updating the app, or switching to 7-Zip, The Unarchiver or an online opener, solves it.

Quick Way to Diagnose the File

If you're not sure which problem you have, upload the archive to an online RAR opener. It reads the archive before extracting anything and reports what it finds: the RAR version, whether it's encrypted, whether the data ends early, or whether it's a different format altogether.

Summary

Check the file size first, then look for missing parts, then the password. True corruption is less common than incomplete downloads, and a quick look at the first few bytes will tell you whether the file is a RAR at all.