Netfabb is an awesome STL viewer & repair tool

We ultimately want the Shapeways upload filters to be perfect. We’d like us to be able to repair any file automatically. And even though each day brings us one step closer to that goal, we are not there yet. Specifically to help you guys out with your wall thickness issues we went on the hunt for a software tool that you could download right now. We hoped that the right tool would make life a lot easier for you guys. After months of looking and two weeks of testing by five of us, we’ve found one. It is called Netfabb Studio Basic and it rocks.

Previously we helped you guys by showing you Meshlab, a free and open source tool that is great for polycount reduction, mesh resurfacing, normals recalculation, viewing issues with models for 3D printing and converting. We also have shown you Accutrans, a free for 30 days, tool that is great for converting from lots of different file types and scaling. In addition to these tools there is a great closed source commercial package out there called Magics by Materialise, a 3D printing service bureau. This tool even goes as far as to automatically repair your STL files in some cases. It is a great tool, the only problem with it is that it costs $7000. Materialize even has a service called STLFix where you can repair your STLs. There is a free version of Magics called mini-Magics. But this is only an STL viewer and doesn’t let you repair anything. There is also 3D scanner software such as Polyworks and GeoMagic that are meant specifically for repairing meshes made from scans. These are also good but as Magics, they are also expensive.

There really was no commercial alternative to Magics, until now. Netfabb Studio views STLs, repairs STL files automatically, scales them, inverts normals, measures STLs and lots more. This tool blew me away. The second best thing about it is that Netfabb currently costs $399. The best thing about Netfabb? There is a free version of it that you can download. This does a lot of the things the commercial version.

With the free version of Netfabb Studio Basic you can:

  • automatically close holes
  • automatically invert face normals (inverted or flipped triangles)
  • automatically repair non-manifold errors
  • easily measure the wall thickness of STL files
  • easily measure dimension and volume of your model
  • easily scale STL files
  • stitch triangles
  • manually remove, invert and add faces triangles and shells

One huge word of caution before you collapse from joy. Even though Netfabb is a great free tool it can not solve all your problems. A lot of files can simply not be automatically repaired. The free version also does not remove intersecting triangles. The software can not repair with ‘degraded triangles.’ You can select and remove some shells but the free version does not have a way to automatically reduce many shells to one. So this will not make all your STL problems magically go away. We’ve been testing it for two weeks and we’re impressed but realize that no software tool can fix everything automatically. It is a huge step forward though.

Read on to see how to use and what you can do with the Netfabb Studio Basic STL viewer and repair tool.

You can download Netfabb Studio Basic here. Tell them Joris sent you. Once you download you have to wait ten seconds until it starts every time. You can choose to give them your email to register for free and after that you don’t have to wait each time. 

If you’ve used Magics or Mini-Magics the user interface will be seem quite familiar.

You can import parts under Project -> open. And you can export to STL under Part -> export part as STL. With the scroll wheel of your mouse you can zoom in or out on an STL part. By holding down the mouse right click, you can rotate a STL part. When a part is selected it will turn green.

How to measure wall thickness with Netfabb Studio Basic?

the right of top menu row there is a ruler. This opens a right panel
with a lot of measuring options. You can measure point to point,
radius, angles etc. To measure wall thickness select wall thickness in
the panel and click on a wall you want to measure. Presto.

How to automatically repair holes, non-manifold areas, open edges, flipped triangles in STLs?

on the Red Cross logo. Click update on the right panel to see what is
wrong with your model. Then click on Automatic repair and click on execute.
Click on update to see what happened. In some cases your
model will now be completely repaired. Click on Apply repair to save
the changes.

The picture above shows you a model with 6 inverted normals. They are listed in the right panel under invalid orientation and are shown in red on the model. Below you can see the repaired STL.

It is important to remember to click update to see if you’ve repaired your file. Also don’t forget that changes won’t be applied to your model until you click on Apply repair. Below are two screen shots of the right panel of the repair screen showing you how Netfabb Studio Basic repaired 32 border faces and 16 holes automatically. 

How to do an analysis of your STL?

In the top menu row click on the globe that has a square in its left bottom corner. Click on standard analysis. The right panel will now display volume, triangles, points, shells, bad triangles etc.

How to scale your STL?

the top row of the normal menu there is a sphere with two arrows. Click
on the sphere, fill in the scale factor you need and presto. Larger
than the decimal increases the size of the model. Smaller than the
decimal reduces the size of the model. Filling in 0.2 will make the
model a fifth smaller. 1.2 makes it a fifth bigger. 2 doubles the size

How to manually repair STLs?

In the top row there are green
icons. The triangle stands for triangles, the pentagon is for surfaces
and the rectangle is for shells. Once you’ve selected an element and
clicked on the respective triangle, shell or surface it will turn
green. Then you can in the next column over choose to remove it, flip it
or add to it. If you select a triangle you can right click to see the options.

Please note that the top menu changes depending on if
your in the repair menu or in the general menu. You can easily switch
between these and parts using the top panel.

How to invert your selection?Toggle selection.

Lets say you have one good shell and a bunch of silly ones that are a mistake. Click on the green rectangle in the repair menu. Select the good shell, press toggle selection. This inverts your selection meaning that once you do it you’ve selected all the other shells. Click on the model, then right click. You can now remove all the shells except for the good one in one go with Remove triangles.

STL, but I hate the STL file format, I don’t have it, it sucks.

You can convert a lot of file types into the STL format using Meshlab. The following files are supported by Meshlab: PLY, OFF, OBJ, 3DS, COLLADA, PTX, V3D, PTS, APTS, XYZ, GTS, TRI, ASC, X3D, X3DV, VRML, ALN. You can download Meshlab here.

Allrights, this should get you started. I love Netfabb and it would be great to get feedback to see if it helps you guys. You can also email your questions, comments, bugs and things to Support at Netfabb. They’re an enthusiastic team and they would love to hear your feedback also. You can download Netfabb here, enjoy!

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  1. Madox

    Thanks Joris… going to give this a try.

  2. Bob Hearn

    Unfortunately, it’s Windows only.

    1. Alex

      Hello Bob,
      actually there is a Linux version, even though in a beta stadium and quite untested. So at the moment we prefer not to release anything for download. If you would like to help us and obtain a linux binary, feel free to contact me at

      Thank you very much,

  3. Anonymous

    Actually I’m a Mac guy. I use Rhino; there are some basic repair tools in it. But they’re not always good enough. I hear Blender has better repair tools, but I am completely put off by its interface, or lack thereof.

  4. { D F }

    I tried Netfabb, it looks nice. However, people working with COLLADA files instead of .stl will face a problem.
    I also tried the “repair” utilities. They can be very effective sometimes… but not always.

    1. Joris Peels

      yeah, it is for STL but you can easily convert between STL and COLLADA using meshlab.

      No STL repair tool always works. I tried to convey that in the post.

  5. jessie

    I encountered a strange problem with fixing non-manifold errors in Nebfabb. I fixed the errors displayed by using the automatic repair option, applied it, then the # of bad triangles, invalid orientations turned into 0’s. but after I saved the changes, re-open the fixed image with Nebfabb, I saw the same errors again.
    is it that those errors just can’t be fixed?

    1. Joris


      It is true that some errors can not be fixed.

      But, the issue that you’ve found sounds like a bug. You can tell Netfabb about it by emailing them at support (at) netfabb (dot) com

  6. Poolster

    I was using miniMagics before and couldn’t fix my multiple shell problem. With Netfabb It couldn’t fix the problem either, but it did show me where the shells were and I was able to stich them together by re-working my CAD file. At least I knew where the problem was with Netfabb, and that saved me!

    Thanks for this great page Joris!

  7. greanie


    Netfabb looks nice. However, the problem I would like to eliminate is having to find thin features. I can measure any point to any point with my CAD software but if my model gets rejected because of wall thickness, then there is something I have missed. Is there a tool that will look for the minimum thickness / point to point distance on a part?


  8. Anonymous

    looked into meshlab, what a failure that was. no x86 download. netfabb looks promising, I plan to play with it a little more but I fear it’s just a giant waste of my time. (Trying to repair an stl of a guy fawkes mask, the program is reading the back of the mask as a hole and there is no volume.. 0.00mm thick everywhere.)

  9. John R

    OK thank you – I am a convert. 😉

    After days of stuffing around trying to eliminate multiple shells, holes and other issues Netfabb has done a great job. Learning the workflow for different operations was however a challenge.

    Would be helpful to highlight the fact that shell repair is a manual exercise.

    It would also be helpful in your instructions above to add a note at the start of the section between the title and the first sentence: “Start by pressing the repair button (Red Cross)” other wise the triangles to which you refer are not visible unless there is a setting I am not aware of which has them in the top menu bar at all times.

    Title – How to manually repair STLs?

    First sentence – In the top row there are green icons.

  10. Annonymus

    check meshmixer
    yes it fix automatically holes gaps
    it capable to changing density of a mesh, partially or the whole
    it makes Booleans between shells
    if there are shell enclosed in other shell, it can separate
    and a lot more..

    it developed by an invidual, Ryan Snidth but now it is under autodesk …
    Ryan an autodesk developer..

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