Best Free Lego Building Software


Lego was the classic brick building toy of yesteryear. Nowadays, it's moved in all sorts of technological directions, including elaborate Mindstorms; robotics based on programmable bricks originally conceived for educational purposes, and something approaching computer aided design (CAD).

Without pretending to compete with the feel of the real thing, there's Lego building freeware out there that's just crying out to be used as a virtual toy.

Fancy clicking some virtual bricks together on your PC? Over the years, the Lego toy brand has become increasingly oriented towards prebuilt models making it more difficult to think outside the predesigned blocks. But on a computer you can let your fantasy rip without having to shell out for designer components. And Lego building programs are a spatially intriguing experience for youngsters of all ages.

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Go to details...  Go straight to the Quick Selection Guide


Lego Digital Designer in build modeLego Digital Designer (LDD) is the official Lego CAD-like program for Windows and Mac. For many this smart toy will be a clear first choice. The graphics and controls are excellent. If you're accustomed to Google Earth, then you'll probably soon feel at home navigating in 3D on the virtual grid, moving building blocks and turning them through 90 degrees.

A child-friendly user manual is provided, and there’s also a series of brief video tutorials on the LDD site to help you get started. The company does try to attract you towards their product range. But it's easy enough (for an adult at least!) to go one's own way.

In 'Build mode', there are lots of tool options and other stuff to explore. You can save your new Lego constructions as you go. It's also fun to take prebuilt models to bits, and of course you can also reconstruct them or dream up your own creations with Mindstorms components. However, even if you own a physical Mindstorms set, scope for serious design is limited by LDDs inability to rotate pieces through any angle.

Switch to 'View mode' to see your constructions against several different backgrounds (with sound effects), such as the sea or outer space. You can get the whole construction to explode in a flash... and then gently drift back together again. You can also take screenshots on the fly. There's now also the possibility to upload and share your LDD creations over the Internet, though you have to comply with certain brick choice restrictions (for example, my illustrated attempt didn't pass the test).

It's up to you to mix the build and thrill. For some children, this free toy might be a fun first step towards the  world of creative 3D computer graphics and CAD.


BlockCad Leggo like building programBlockCad is unofficial ‘Lego-like’  freeware. So the program is completely free from advertising material. BlockCad has been in development since 1998 when the Swedish programmer built it for his own children. Unsurprisingly, it has a less up-to-date look and feel than the commercially backed Lego Digital Designer and a slightly less extensive choice of building blocks and joins.

Nevertheless, BlockCad has a stimulating set of building options (you can save your work) and the interface is fairly intuitive to use despite a relative lack of text. There are plenty of hotkeys and a schematic user manual is provided, but expect a learning curve. You can display your work against any background image file of your choice.

All in all, BlockCad is a remarkable individual achievement and may be the Lego-like program of choice for less powerful computers.


More advanced Lego freeware:  Any Lego fan with an interest in CAD will probably want to check out LDraw in conjunction with LeoCAD and perhaps also MLCad (LDraw download links here).

The independent LDraw community project (recognized by Lego) provides a large collection of freeware tools for serious modeling, design and imaging. LDraw is also partially compatible with Lego Digital Designer. So it's an obvious step up for computer modeling. But it's more than a simple toy. LDraw and LeoCAD could be the way to go for Mindstorms enthusiasts wanting to construct programmable digital designs.

These lego-like CAD freeware programs run on Windows 98 and above (32-bit), Mac and Linux. Mac users may also like to check out Bricksmith.


To be reviewed: SR 3D Builder (Windows only) is an ambitious Lproofreadego design freeware project which is currently under development - think beta testing. The brainchild of an Italian enthusiast, SR 3D Builder should be worth watching as it develops. Use of LDraw suggests that SR 3D Builder may have potential for some quite advanced capabilities. The documentation is extensive, with a growing user manual in reasonably comprehensible English; video tutorials are also available, but the high speed and absence of voice over makes them awkward to follow. One for Lego software enthusiasts to explore? 

Please help us by rating this review.

Related Products and Links

You might want to check out these articles too:

Quick Selection Guide

Lego Digital Designer
Gizmo's Freeware award as the best product in its class!

Runs as a stand-alone program on a user's computer
Good 3D graphics, intuitive controls, advanced building options, upload and share online
Many commercial aspects, large download, resource hungry
185.04 MB
Unrestricted freeware
Windows XP, Vista, Win 7; Mac version also available.

German language option, user manual

Runs as a stand-alone program on a user's computer
Lightweight 'Lego-like' program, many building options, use own backgrounds (image files), no commercial affiliation
Less modern user interface, learning curve, development has slowed down
828 KB
Unrestricted freeware
Windows 95 to XP, also works on Vista 32 bit.

Instructions also available in French and Spanish.
v3.18 released 4 January 2005


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This page is about: lego building program, lego builder, lego building games, lego construction program, lego freeware, lego cad, lego digital design

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Average: 4.5 (49 votes)
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by RicketyEng (not verified) on 31. October 2011 - 4:48  (82445)

I tried to download LDraw but when I try to run the .exe it claims it is not compatible with my 64-bit system. Has anyone else experienced this or know of a solution?

What I'm mostly interested in is the SR 3D Builder but the site I found to get it from lists LDraw as a requirement. Any more information or clarification on issues like this would be helpful.

Also, thanks for the review! This was exactly what I was looking for when I went looking for information about what Lego design software is available.

by xSergio74 (not verified) on 31. December 2011 - 15:22  (86279)

SR 3D Builder is standalone.
It installs all required lDraw part library and is ready to be used.
Just follow the requirements needed on its official site download page and you will be done in 15 minutes.

(author of SR 3D Builder)

by Robin Chang (not verified) on 1. May 2011 - 3:00  (71210)

Bob, I'm rather disappointed that you haven't done a more thorough review of LDraw and SR3D, seeing as they aren't listed under the Quick Selection Guide.

LDraw is generally used by older FOL's who are frustrated by the lack of options / colors / part variety in LDD. And whereas LDD is marketed towards younger FOLs who simply want to create some "cool 3D legos", LDraw can be easily expanded with various third-party tools, and is an open-source community driven standard - if a part is missing in LDraw, a user can actually create it themselves and submit it for community approval, whereas LDD users are at the mercy of updates from the TLG.

As I am an active user of the LDraw suite and have contacts within the LDraw community itself, if you are interested I can also provide a full review for LDraw to balance out the overall review.

by GregD (not verified) on 6. July 2012 - 18:43  (95816)

@ Robin Change (or anyone else who can answer): the mac version of the LDraw software was last updated in 2000 according to the LDraw history site. Will LDraw still work on the newer (<5 year old) Intel-based core-duo macs? Or is there a newer version of the software for mac users that I can't find?

by Bob on 1. May 2011 - 12:46  (71221)

Hello Robin

I can see you have some good ideas to enhance the review, which currently cuts out about where LDraw kicks in. I fully agree with your proposal to round out the overall review, while hopefully also satisfying the needs of "average players" just looking to, well, play around with some virtual 3D lego without a steep learning curve. I would genuinely be very happy if you'd like to come in  - just send off this form -  and you'll be sure to find plenty of support.

Best regards

by amy (not verified) on 3. April 2011 - 10:27  (69396)

how can i download?

by Bob on 3. April 2011 - 10:28  (69397)

Which program are you looking to download? I've updated the links for BlockCad and LDraw. Hope that helps.

by fili martinez (not verified) on 6. March 2011 - 18:04  (67530)

this is cool

by immanuel (not verified) on 25. November 2010 - 4:33  (61640)

are you sure that the lego ldd contains no viruses?

by Bob on 25. November 2010 - 11:11  (61646)

Scans clean for me... What would a company like lego have to gain from distributing a virus in their software? Some users might have advertising ("adw4re") concerns about this program, but that's a different issue.

by Anonymous on 12. May 2010 - 19:06  (49663)

for the ones interested in it, I have released latest version of SR 3D Builder on 2010.05.11



by Anonymous on 10. April 2010 - 14:50  (47376)

It's also worth noting that one can order custom sets via LDD. So, if that car you've built in your computer looks snazzy enough, you can send for it and build it in real life.

by Bob on 12. April 2010 - 8:06  (47474)

Yes, but that costs money. This freeware site only reviews the genuinely free aspects of freeware.

by Anonymous on 13. March 2010 - 19:52  (45505)

Have anybody of you tried SR 3D Builder?

This is the website:

Don't miss the videos!!

by Anonymous on 9. April 2010 - 13:21  (47298)

Just a warning - Avira gives this warning when visiting the above URL

In order not to compromise your security, this page will not be accessed

A virus or unwanted program was found in the HTTP data of the requested page.
Requested URL:
Information: Contains HEUR/HTML.Malware suspicious code


by Bob on 12. April 2010 - 8:02  (47473)

Thank you - we are aware of this false-positive alert by Avira heuristics for this web site (presumably affecting only some Avira versions/installations). There is actually a note [in italics] in the article about this longstanding Avira issue.

by MidnightCowboy on 9. April 2010 - 15:57  (47306)

Not sure why that should be. I have Avira 10 which gives no warning, the site is green rated by WOT and has zero threats according to Norton Safe Web.

by Ritho on 9. April 2010 - 20:28  (47320)

No warning from Avira for me either.

Also tested the url at a several different online url malware/virus scanners, and it came up clean.

by Bob on 15. March 2010 - 23:17  (45626)
Thanks for the heads-up: SR 3D Builder is in line for review.
It's good to have more lego freeware around and SR 3D Builder looks like it deserves careful evaluation... despite the rather dazzling color scheme unscathed on the developer's website. I notice SR 3D Builder uses LDraw, suggesting that this program may have potential for some quite advanced capabilities. Like BlockCAD, SR 3D Builder doesn't have the hands-on, intuitive feel of Lego Digital Designer (a pity since the commercial angle of LDD seems to be getting increasingly intrusive - something that concerns me). However, I do see that the developer of SR 3D Builder has worked up a nice looking set of video tutorials on YouTube, which I look forward to exploring to try to get a feel for the program. Will report back...
(Note: Avira's standard heuristics currently block this page - but that's quite clearly a false positive.)
by Anonymous on 23. March 2010 - 12:08  (46051)

I'm the author of the program.
For a 'quick' learning of application features, read the manual
For a quick keymap functionality, check online help with F1

Hope you like it

Best regards


by Bob on 23. March 2010 - 14:15  (46055)

Thanks Sergio - SR 3D Builder is definitely in line for review here... fairly presto... Once I've finished juggling a few other programs and things ;)


by Bob on 4. February 2010 - 12:33  (42766)

This article from the BBC website talks a bit about some of the ways adult Lego enthusiasts like to use LDraw:

by Anonymous on 9. November 2009 - 12:13  (36261)

I find LDD (v 3.0.9) very easy to use.
The only problem is a missing library with older parts.
but that is due to the fact that you need to use LDD to buy your own design.
But watch out, the price at pick a brick is much cheaper.

by Anonymous on 19. July 2009 - 14:44  (25368)

Lego Digital designer is very nice but is very uneasy tous in the first place and has a big problem: it contan use only latest brick and only from a limited amount of Lego sets.
That coudl be a very powerfull tool however but Lego need a little more work to allow "older" people touse it for their own pieces and models and not only to be able to create models that you want to order bricks for...

by new61 on 7. April 2009 - 21:03  (19485)

I tried Lego Digital Designer a few years ago... I was around 8 years old. If I remember correctly, it was really hard to use. I might try it again now that I am a bit more intelligent. ;)

by Bob on 8. April 2009 - 9:47  (19522)

Yes, more feedback please. All ages and computer experience...

(Early versions of Lego Digital Designer may have been a bit buggy)