RAR Extractor

The RAR Format: Compression as a Science

RAR — Roshal Archive — was created by Eugene Roshal in 1993 and is maintained by his brother Alexander through win.rar GmbH. Unlike ZIP, which is an open specification implemented by hundreds of tools, RAR is a proprietary format: the decompression source code (unrar) is freely available, but the compression algorithm is licensed. That single asymmetry explains both RAR's strengths and its ecosystem quirks — anyone can extract RAR, but only WinRAR (and tools that embed its code) can create it.

RAR vs ZIP: Where Each Wins

ZIP compresses every file independently with DEFLATE, which is fast and universal but leaves ratio on the table. RAR typically achieves 10-30% better compression than ZIP on mixed content thanks to a larger dictionary window (up to 1 GiB in RAR5 versus ZIP's 32 KiB), PPM-style context modeling for text, and specialized filters for executables, audio, and images. RAR also pioneered solid archiving, where all files are compressed as one continuous stream — excellent for many small similar files, at the cost of making random-access extraction slower. Where ZIP still wins is ubiquity: every OS opens .zip natively, while .rar requires a third-party tool — which is exactly what this page provides in the browser.

RAR4 vs RAR5: The 2013 Redesign

RAR5, introduced with WinRAR 5.0, replaced the aging RAR4 container with a cleaner design: headers use variable-length integer encoding instead of fixed structs, checksums upgraded from CRC32 to BLAKE2, encryption moved to AES-256 in CBC mode with optional encrypted headers that hide even the file list, and timestamps gained nanosecond resolution. RAR5 also supports larger dictionaries and drops legacy features like the old recovery volumes in favor of a redesigned recovery record. This tool detects the version by signature byte 7 (0x00 = RAR4, 0x01 = RAR5) and displays it in the results header — the same unrar 6.x decoder handles both formats transparently.

Encryption and Recovery

RAR encrypts file data — and optionally the archive header — with AES. When only member data is encrypted, the file list is still readable and encrypted entries show a lock icon; when the header itself is encrypted (RAR5 -hp mode), nothing can be listed until the correct password is supplied. RAR's optional recovery record adds Reed-Solomon parity data that can repair limited corruption — a feature this tool reports but does not use for repair, since browsers lack the recovery workflow.

Official Decoder in WebAssembly

This tool embeds the official unrar library — the same C++ decoder that ships inside WinRAR — compiled to a ~200KB WebAssembly module loaded on demand. Because it is the reference implementation rather than a reverse-engineered parser, edge cases like solid streams, RAR5 BLAKE2 checksums, Unicode filenames, and AES-encrypted members behave exactly as they do on the desktop. Your archive is read with the local File API and decoded entirely in memory; nothing is uploaded, which you can confirm in your browser's Network tab.

When You Will Meet a RAR File

RAR remains common in software distribution, game modding, Usenet downloads, and backup sets — especially archives created on Windows between 1995 and today. Typical situations this tool handles:

• Opening a .rar on macOS, Linux, or ChromeOS where no extractor is installed — drop the file in and get your contents as a ZIP or individual downloads.
• Inspecting before extracting — preview the full file list and sizes before committing to a download, useful for large archives where you only need one or two members.
• Legacy RAR4 archives from old software CDs, driver bundles, and backup sets that modern tools sometimes handle inconsistently.
• Password-protected archives shared for sensitive documents — decrypt locally without handing the password to a server.
• Checking a suspicious archive — because extraction runs in a browser sandbox, a hostile archive cannot execute code or write outside the download you explicitly request.

Limitations to Know

Multi-volume archives (.part1.rar with .r00/.r01 companions, or RAR5 .partN sets) cannot be fully extracted — the decoder sees only the single file you provide, so members stored in other volumes report a clear error rather than failing silently. RAR creation is impossible here and everywhere outside WinRAR: the compression side is proprietary, which is why export is offered as universally-readable ZIP. For other formats, use the dedicated ZIP tool, TAR tool, or identify an unknown file first with the file type detector.

Privacy and Security

Your archive never leaves your machine. The unrar engine executes as WebAssembly inside the tab, file bytes stay in browser memory, and extracted downloads are created via local object URLs. No cookies, no accounts, no telemetry on file contents — verifiable in the Network tab. The tool also sanitizes member paths when repacking, blocking zip-slip style entries (../../etc/passwd) that malicious archives use to overwrite files outside the target folder.