Free RAR, 7Z, TAR and ZIP Converter: No Sign-up, No Upload
This archive converter is free, needs no sign-up or login, and your files never leave your browser. Nothing is uploaded, no watermark is added, and no account is needed. Drop in an archive, choose the format you want, and the contents are unpacked and repacked on your own device.
Archives usually hold a lot of files at once, often private ones: backups, project folders, exported documents. Sending a whole archive to a website just to change its format is a real exposure, so here the unpacking and repacking happen in the tab and nothing is sent to us or anyone else. Some archive types need a small engine that your browser downloads once the first time, about 1.5 MB, and it contains no file of yours.
Common cases are turning a RAR or 7Z into a ZIP that every computer opens, packing files as TAR or TAR.GZ for Linux and macOS, and recompressing a single GZ, BZ2, XZ, LZMA or ZST file as ZIP or 7Z. Add several archives at once and download the results together as a ZIP.
- Free
- No sign-up
- Never uploaded
- No watermark
Your files are converted on your device and never uploaded.
How to convert
- Add your archives by dragging them onto the page or by using the file picker.
- Check the detected format of each archive, which is read from the file content.
- Choose the target format: ZIP, TAR, TAR.GZ or 7Z.
- Read the note about the one-time engine download if the pair needs one.
- Press Convert and wait while the contents are unpacked and repacked.
- Download one result directly, or several together as a ZIP.
Features
- Opens ZIP, 7Z, RAR, TAR, GZ, TAR.GZ, BZ2, XZ, LZMA, ZST, CAB, ISO, CPIO, TAR.BZ2 and TAR.XZ.
- Creates ZIP, TAR, TAR.GZ and 7Z, and a TAR can also become a GZ.
- Runs in your browser with no upload, no sign-up and no watermark.
- ZIP, TAR, GZ and TAR.GZ conversions need no engine download.
- Reading 7Z, RAR and the other formats, or writing 7Z, loads a one-time engine of about 1.5 MB.
- Format detection by file content, so a wrongly named archive is still recognised.
- Batch conversion with one ZIP download.
- Single-file compressors such as GZ, XZ and ZST can become ZIP or 7Z.
Supported formats
| Format | Read | Write | Notes |
|---|---|---|---|
| ZIP.zip | Yes | Yes | The most common archive format, opened natively by Windows, macOS and Linux. |
| 7-Zip (7Z).7z | Yes | Yes | Archive format of the 7-Zip tool, usually the smallest of the common formats. |
| RAR.rar | Yes | No | RAR is a proprietary format: its encoder is not available, so RAR files can be opened but not created. |
| TAR.tar | Yes | Yes | Tape Archive: bundles files together without compressing them. |
| GZ.gz | Yes | Yes | gzip compresses a single file or stream, and is the compression behind .tar.gz. |
| TAR.GZ.tgz | Yes | Yes | A TAR archive compressed with gzip. |
| BZ2.bz2 | Yes | No | BZ2 can be opened but not created here; use ZIP or TAR.GZ. |
| XZ.xz | Yes | No | XZ can be opened but not created here; use ZIP, 7Z or TAR.GZ. |
| LZMA.lzma | Yes | No | LZMA can be opened but not created here; use 7Z or ZIP. |
| Zstandard (ZST).zst | Yes | No | ZST can be opened but not created here; use ZIP or TAR.GZ. |
| Cabinet (CAB).cab | Yes | No | CAB can be opened but not created here; use ZIP. |
| ISO disc image.iso | Yes | No | ISO images can be opened but not created here; extract the files and use ZIP. |
| CPIO.cpio | Yes | No | CPIO can be opened but not created here; use TAR or ZIP. |
| TAR.BZ2.tbz | Yes | No | TAR.BZ2 can be opened but not created here; use TAR.GZ. |
| TAR.XZ.txz | Yes | No | TAR.XZ can be opened but not created here; use TAR.GZ. |
About the formats
ZIP, 7Z and TAR.GZ
ZIP is the most common archive format and is opened natively by Windows, macOS and Linux. It compresses each file separately, so single files can be extracted quickly. 7Z is the format of the 7-Zip tool and usually compresses more than ZIP, using LZMA. TAR.GZ is a TAR archive compressed with gzip, the usual format for source code releases on Linux and macOS.
If you are sending files to someone and do not know what they use, ZIP is the safe choice. If size matters more than convenience, 7Z is worth trying, but the recipient needs a tool that can open it.
TAR, GZ and the single-file compressors
TAR bundles files together without compressing them, and is normally combined with gzip, bzip2 or xz. GZ compresses one file or stream and is the compression behind TAR.GZ. BZ2 usually compresses better than gzip but is slower, XZ and LZMA use LZMA compression for a high ratio, and Zstandard (ZST) is a fast compressor developed at Facebook (Meta) that is increasingly used for packages and backups.
A GZ, BZ2, XZ, LZMA or ZST file holds a single compressed file, so converting it gives a ZIP or 7Z containing that file.
Formats you can open but not create
RAR is proprietary and its encoder is not available, so RAR files can be opened but not created. The same applies to BZ2, XZ, LZMA, ZST, CAB (the Microsoft installer archive), ISO disc images, CPIO (used inside RPM packages), TAR.BZ2 and TAR.XZ. For these, the usual route is to convert to ZIP or TAR.GZ.
An ISO is an exact copy of the files on an optical disc. Converting one extracts the files into an archive that you can open anywhere, but it does not make a bootable disc.
Why some conversions download an engine
ZIP, TAR, GZ and TAR.GZ are handled directly by the page. Reading 7Z, RAR, BZ2, XZ, LZMA, ZST, CAB, ISO, CPIO, TAR.BZ2 or TAR.XZ, and writing 7Z, uses a WebAssembly engine of about 1.5 MB. Your browser downloads it once and keeps it, and the page shows the size before it starts. Only the engine is downloaded, never your files.
Privacy: how it works
- Your archives stay on your device. The page reads each file with the browser's file API, converts it with code running in the tab, and hands the result back as a download. No upload happens, so there is no copy of your file on our servers to protect, delete or leak.
- There is nothing to sign up for and no login. The converter does not ask for an email address, and it does not need to know who you are to do its job.
- Some conversions use a WebAssembly engine that your browser downloads once, the first time you need it. Only the engine is fetched, never your file, and the page shows the approximate size before it starts. Your browser caches it, so later conversions skip the download.
- You can check the claim yourself: open your browser developer tools, watch the Network tab while a file converts, and you will see no request that carries your file.
- An archive is unpacked in your browser memory before it is packed again. That is why a very large archive needs enough free memory on your device, and it is also why nothing about its contents has to be sent anywhere.
Tips
- Choose ZIP when you are not sure what the recipient uses, because every major system opens it.
- Convert RAR to ZIP before sharing, since RAR needs extra software on many computers.
- Use TAR.GZ for source code and Linux or macOS deployments.
- Try 7Z when size matters, and check that the people who receive it can open 7Z.
- Close other heavy tabs before converting a very large archive, because it is unpacked in memory.
- Convert big archives one at a time on a phone or an older computer.
- Extract an ISO only to get its files, not to burn a disc.
- Check the file count after conversion to confirm nothing was missing.
- Remember that a GZ holds one file, so a folder needs TAR first.
Frequently asked questions
Is it really free?
Yes. There is no price, no trial, no credit card and no watermark added to your results. Ulkaa Tool does the conversion with your own device, so there is no server bill to pass on to you.
Are my files uploaded?
No. Your archives are read and converted inside your browser and are never sent to Ulkaa or to anyone else. The result is created on your device and you save it from there. Some conversions load a small conversion engine the first time you use them. That download is the only network traffic, it contains no file of yours, and your browser keeps it for next time.
Do I need an account?
No. There is no sign-up and no login. Open the page, add your files and convert. An Ulkaa account is not needed for anything on this tool.
Is there a file size limit?
No limit is set by us. The real limit is your device: the conversion uses your own memory and processor, so very large files can be slow or fail on a weak phone or an older computer. Close other heavy tabs and convert archives one at a time if a big batch struggles.