What Is a RAR File? How It Differs From ZIP
RAR is another common compressed archive format, similar in basic purpose to ZIP — bundling and compressing multiple files into one — but built by a different company with a different underlying compression technology, and with a notably different relationship to built-in operating system support.
What makes RAR different from ZIP
Functionally, RAR does the same fundamental job as ZIP: it bundles multiple files together and compresses them. Under the hood, RAR generally achieves somewhat better compression ratios than standard ZIP for many file types, meaning a RAR archive can end up smaller than an equivalent ZIP of the same files. The tradeoff is compatibility: RAR is a proprietary format, and unlike ZIP, most operating systems don't include native RAR support out of the box.
Why you need separate software (or a browser tool) for RAR
Because RAR isn't built into most operating systems the way ZIP is, opening a RAR file typically requires dedicated extraction software, or a browser-based tool that supports the format directly. This is the most common point of confusion for people who receive a RAR file and find it simply won't open with whatever they'd normally use for a ZIP.
Multi-part RAR archives
RAR archives are sometimes split into multiple numbered parts (like .part1.rar, .part2.rar) for easier distribution of very large files across systems with upload or attachment size limits. Extracting a split archive requires having every part present in the same location — a common cause of failed extraction is simply having downloaded some, but not all, of the parts.
Why RAR remains common despite ZIP's built-in advantage
RAR persists mainly in contexts where its better compression ratio genuinely matters — sharing very large files where every bit of size reduction counts — and among communities where RAR-compatible software is already standard. For everyday, general-purpose file sharing, ZIP's near-universal built-in support usually makes it the more practical default choice.
Extract Archive opens RAR files directly in your browser, no separate software required. If you'd prefer to keep the contents in a more universally native format going forward, Convert Archive can turn a RAR into a ZIP.