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RAR to STL: open the archive and get the model

Drop the .rar below. It is unpacked inside your browser, every model in it is listed and shown in 3D, and you download the one you want as STL — or as 3MF, OBJ or STEP. Nothing is uploaded and there is nothing to install.

Your file is opened by your own browser and never sent to a server. There is no upload, no account and no copy of it anywhere but on your computer.

A RAR protected by a password, or split across several files (part1.rar, part2.rar…), cannot be opened here. Unpack those on your computer — the steps below show how on every system — and drop in the model.

If you would rather unpack it on your computer

For a password-protected or split archive, or if you just want the folder. Every operating system either does this out of the box or does it with one free program.

  1. Windows 11

    Right-click → Extract All

    Windows 11 has read RAR files since late 2023, with nothing to install. Right-click the file, choose Extract All, and pick where the folder should go.

    On Windows 10 this option is not there. Install 7-Zip, which is free, and use the same right-click menu.

  2. macOS

    Open with → The Unarchiver

    macOS opens ZIP files by itself but not RAR. The Unarchiver is free from the App Store; after installing it, double-clicking the .rar unpacks it into a folder beside itself.

    Keka is a good alternative and handles more formats.

  3. Linux

    unar file.rar

    Install `unar` or `unrar` from your package manager and run it on the file, or right-click and use Extract Here in your file manager once one of them is installed.

  4. Then bring the model here

    Inside the folder you will find the actual model files. Drop the one you want onto the box at the top of this page, or onto any converter on this site.

What happens when you drop a RAR here

The archive is unpacked in your browser, in a background thread, by RARLAB’s own decoder — the same unRAR code WinRAR is built on, compiled to run in a web page. It opens old RAR 4 archives, current RAR 5 ones, and solid archives where every file is compressed together.

Then every model inside is read: STL, OBJ, 3MF, STEP, PLY, GLB and the rest of the formats this site opens. Each becomes its own named object in the list under the 3D view, so you can see which bracket is which, hide the ones you do not want, and download only the one you need. Readmes, licences and photographs are skipped.

The decoder is about 200 kilobytes, fetched once from a public code network the first time you drop a RAR and kept by your browser after that. Your archive is not part of that request and never leaves your computer.

Why most RAR to STL converters upload your file

Because unpacking a RAR used to need a server. The format’s compressor is proprietary, and for a long time the only practical way to offer "RAR to STL" on a website was to upload the archive, unpack it on the site’s own machine, and send the result back.

That is fine for a free model off Thingiverse. It is not fine for a client’s parts, a commercial model you paid for, or anything under an NDA — and the upload is the slowest step anyway. Here the archive is opened where it already is.

What you will find inside

Usually several model files, a readme, a licence and a few photographs. Most downloads from model sites are packaged this way, and the models are almost always STL already — in which case "converting" is really just getting the one you want out, which the list under the 3D view does.

If a model inside is a SolidWorks part, a Fusion archive or a Blender file, no browser tool can read it, and the message under the 3D view says which file it was. The guides for those formats explain what to do instead.

RAR or ZIP, next time

If you are receiving files from somebody regularly, it is worth asking for a ZIP. A ZIP opens on every computer made in the last twenty years with no software to install, and it works here exactly as a RAR does. For 3D models the compression difference is close to nothing: an STL is mostly repeated floating-point numbers and both formats squeeze it by about the same amount.

Where we can actually help

A ZIP works exactly the same way. And once the model is out, these are the usual next steps: into 3MF for a slicer, or a check that it will print.

Questions

Is my RAR file uploaded?
No. The archive is unpacked by your own browser and the models are read there too. The only thing fetched is the decoder itself, once, from a public code network; your archive is not part of that request.
Can I convert the model inside a RAR to something other than STL?
Yes. The format box under the 3D view offers everything this site writes: 3MF for a slicer, OBJ or GLB for a modelling program, USDZ for an iPhone, STEP for CAD.
The archive has several STL files. Which one do I get?
Whichever you choose. Each model is a separate object in the list under the 3D view, named after its file. Leave one switched on to download only that one, or several to get them merged into one file.
Can I just rename the .rar to .zip?
No. The extension is only a label; the compression inside is genuinely different, and renaming it produces a file that nothing can open. You do not need to — drop the .rar in as it is.
My RAR is split into several files — part1, part2 and so on.
A split archive cannot be opened here, because the data for one file is spread across the others. Download every part into the same folder and unpack the first one on your computer; the unpacker finds the rest by itself. Then drop the model in.
The RAR asks for a password.
Only whoever made it can give you that. Unpack it on your computer with the password, then drop the model in.

Where to go next

Related guides

Tools that do part of this here

About these formats

Checked against current software versions on 2026-10-15