Software programs for CNC machining can be a costly affair.
However, if you are on a budget, several free software programs are available using which you can do quite a lot.
In this guide, I review the best free CNC software programs available today.
Further, I have sorted the software programs into categories based on their capabilities.
For CNC Router Machines, you generally have four types of software:
1. CAD software: To create a 2D or 3D graphical model of the part you wish to make.
2. CAM software: To convert the design into G-code understood by control software.
3. Control software: Reads the G-code and converts them into instructions for the machine.
4. Simulation software: Reads the G-code and simulates the tool path to predict errors.
There are software programs designed to perform each of these functions. However, you may also find a single software performing more than one of these functions.
These are the best free CNC software programs in each category in 2021.
Some of these have free and paid versions.
|1||Carbide Create||CAD, CAM|
|2||Easel||CAD, CAM, Control|
|3||Fusion 360 (personal)||CAD, CAM|
|12||Openbuilds Control||G-Code Sender|
|14||CNC Simulator Pro||Simulation|
Best Free CNC Software Programs 
In Microcontroller-based CNC control systems (GRBL/Arduino, Raspberry Pi, TinyG), the process flow is as shown below.
For PC based control systems such as LinuxCNC and Mach3/Mach4, the control part is done by the software itself in the PC.
Best Free All-in-one CNC Software
These software programs are best for those starting their CNC machining journey as they do not have to learn multiple software programs.
It helps you perform CAD, CAM, Simulation, and Control from a single interface.
|Carbide Create||Yes||Yes||Only with Carbide 3D CNCs||Yes|
Quick summary of Carbide Create software
It is by far the best free all-in-one software that you can find. You will find all the features rolled into a single package in this software.
Carbide Create is developed by Carbide 3D, a brand that is quite popular amongst the hobbyist crowd for the popular Shapeoko CNC Router.
The software was designed predominantly for the hobbyists and DIY crowd, making it an easy-to-use software.
The simplicity of the software allows you to use it without any CAD/CAM software expertise.
You can use STL and DXF files to create G-code, or you could design 2D shapes using Carbide Create and export them as G-code files.
It also lets you control your router using pre-existing G-code files or G-code files created using Carbide Create.
Carbide Create is an offline software that you can install on your Windows or macOS computers, which is a bonus when you have to run your CNC routers in areas with choppy internet connections.
However, the machining capabilities of Carbide Create are limited to 2.5D machining, and you cannot create or mill 3D parts using this software.
For the Shapeoko users, Carbide Create is the best all-in-one solution, and for the rest, it is an excellent CAD+CAM solution.
Quick summary of Easel software
Easel is an all-in-one CNC software from Inventables, the makers of the popular X-Carve CNC router machines. It can perform CAD, CAM, and control functions using a single software.
It has a library of common shapes that you can use to create designs quickly and convert them into G-code to run your CNC router machine.
The Pro version of Easel lets you work on 4x8 workpieces and allows you to use V-bits for carving with added tools and designs.
Easel is also a photo carving CNC software whereby you can turn any image into a carving using its "Image Trace" feature.
Using this feature, Easel generates the G-Code/Toolpath for the image you upload.
Easel is a web-based software that does not require any installation and can work on any OS platform. However, this also means you require an active internet connection to use Easel.
Unlike Fusion 360 and SOLIDWORKS, using Easel does not require you to have any expertise in designing and has an easy learning curve.
The interfacing between the computer and the CNC router is through a USB cable.
Easel is best suited for GRBL based controllers, but it also works with Marlin firmware if you did some tinkering around.
Inventavbles has a large user base and an active online community that helps you find solutions to your queries.
Easel is commonly used by CNC hobbyists and woodworkers for cutting, engraving, and milling work.
It is an easy-to-use and easy-to-learn software, and you can refer to the dozens of YouTube videos to make it much easier.
In conclusion, Easel is a great free solution for hobbyists and beginners who don't want to fiddle with multiple software programs to operate their CNC router.
Best Free CAD Software for CNC Applications
CAD stands for Computer-Aided Design, and this software helps you create a graphical image of your design in 2D or 3D.
Quick summary of Autodesk Fusion 360 software
Autodesk is popular for its design software programs, and Fusion 360 is an amazing platform for generating 2D and 3D designs.
Fusion 360 can design the parts and convert them into G-code files, making it CAD/CAM software.
You can save design time by using the pre-existing shapes in the software’s library.
The CAM in Fusion 360 adapts to various machining processes and does not limit the capabilities to certain types of machining like the VCarve Pro.
You will need a macOS or Windows computer to install and run the software as it is not cloud-based.
However, you need to connect to the internet every two weeks to keep the software running.
You can use the software for free if it is for personal use. The free version allows you to have a maximum of 10 active documents at a time.
The unpaid version does have some limitations. Features like rendering and simulation are disabled in the unpaid version.
In addition, the automatic tool change and rapid feed features are unavailable in the CAM for the unpaid version.
This increases the job completion time a bit if you are doing heavy work.
Even with such limitations, Fusion 360 provides more capabilities than most free software programs.
Fusion 360 has a free student license that can be obtained if your educational institution has a valid Fusion 360 license.
It has a large user base with good forum support and blogs to help you with your problems.
If you do not mind the learning curve in mastering Fusion 360, it will let you use advanced features for CNC machining.
Quick summary of SOLIDWORKS software
It is a capable and advanced 2D and 3D CAD/CAM software used for industrial and professional applications.
SOLIDWORKS has been developed by Dassault Systems and is a popular choice not only for CNC machining purposes but also for other designing applications.
It is primarily a design software. CAM functionalities are achieved by installing additional add-ons available for the popular CNC router.
SOLIDWORKS is not cloud-based, and you need to install it on your computer. However, due to its wide range of capabilities and features, it is a heavy software.
The recommended system requirements for optimal performance while using SOLIDWORKS is a 3.3 GHz processor with 16 GB of RAM and a compatible graphics card on a 63 bit Windows 10 PC.
It is not completely free, but if you are a startup business or an entrepreneur, you can use it for free for one year, provided SOLIDWORKS accepts your application.
The customer support is good and reliable. The customer portal of SOLIDWORKS provides tutorial videos and training.
Quick summary of Inkscape software
Inkscape is free-to-use offline CAD software that can create vector images. Vector image formats are supported by CAM software programs that create G-code.
DXF is a popular format that most CAM software programs support and can be used to create G-codes.
Inkscape allows you to download and install plug-ins to create G-code from within the software eliminating the need for additional CAM software.
It can be installed and run on Windows, macOS, or Linux operating system-based computers.
Inkscape is a popular design software, and the official website has many tutorial videos to get you started. Furthermore, you can find videos on YouTube to guide you through your design works.
If you want to know about the best CNC software programs including Paid ones, this guide can help you- Best CNC Software
Best Free CAM Software for CNC Applications
CAM is short for Computer Aided Machining, and these software programs generate tool paths from design files and creates G-code that can be understood by CNC router.
Quick summary of OpenBuilds CAM software
OpenBuilds is a CNC manufacturing company that started as an online community supporting the open-source maker movement.
Following the open-source philosophy, OpenBuilds CAM is free to use for anyone.
They also make OpenBuilds CONTROL, a free control software for CNC machines, which I have mentioned in the control software section below.
OpenBuilds CAM is a web-based software and requires you to have an active internet connection to use the software.
The bright side is all the processing is done on the server-side, and you do not need to install heavy software that bogs down your computer.
It can convert DXF, SVG, Bitmap (BMP, JPG, PNG, GIF), and Gerber X274 file types into G-code.
However, to use the G-code, you will have to use OpenBuilds CONTROL, which is a free software program to send G-code.
OpenBuilds CONTROL works with most GRBL based controllers, so you are covered.
On the support end, the huge community of users have a solution to all of your problems and are prompt in guiding you through troubleshooting.
It is a simple and easy-to-use software best suited for hobbyists looking for free software to use with their CNC machines.
Quick summary of FreeMILL software
FreeMILL is a free CAM software that can create G-code from popular design files types.
You can use it as a standalone CAM software or integrate it with SOLIDWORKS CAD software.
The design is minimalistic, and there are no limits on saves, tries, time, or simulations.
The free version has some limitations compared to the paid version but has enough capabilities and features for most hobbyists.
The file types supported by FreeMILL are OBJ, DXF, SMT, STEP, FBX, STL, and SLDPRT.
It can run simulations based on G-code and machine parameters like machine size, type of tool, and workpiece position.
However, you will need a Windows PC to install and run FreeMILL, which can be a drawback for some users.
Best Free CNC Control Software
CNC machines cannot understand the G-code generated by CAM software. Instead, they work based on the control signals they receive.
Control software converts the G-code files to signals that your CNC machines understand.
Free All-in-one Control Software
This software directly generates the control signals for controlling CNC machines and sends them to the machine parts via breakout boards.
Quick summary of LinuxCNC software
It is a control software developed based on the open-source Linux platform making it free to use and modify.
LinuxCNC is a popular machine control software that has been around for a long time and is the root of several control software programs like the popular Mach 3 software.
You can control up to nine axes using LinuxCNC control software. To perform such feats, you need to have good data transfer speeds between the computer and the machine.
Unlike many software programs which are used primarily for running CNC routers/mills, LinuxCNC's GUI is used for CNC lathes as well.
LinuxCNC uses parallel ports to communicate with the machine as parallel ports are significantly faster than USB ports in transmitting instructions.
The system requirements for running LinuxCNC are low, and you can even run it on a Raspberry Pi 4, but it will require you to have a Linux OS-based system.
If your computer does not have a parallel port, you can use ethernet breakout boards to interface your CNC machine and computer using an ethernet cable.
The most popular motion controller board for LinuxCNC is the Mesa 7i76e.
Using an ethernet card aids you in hardware step generation and encoder counting, which is not possible using parallel port interfacing.
As it is an open-source platform, several customized versions are available that add certain functionalities or tweak the user interface and appearance.
LinuxCNC supports pendant control, and it also allows you to interface touchscreen controllers easily.
LinuxCNC has a built-in interface to post questions to the forum page directly for solutions. The large online community is quite active and helpful.
Quick summary of PlanetCNC software
PlanetCNC is a free CNC machine control software for controlling your CNC machine based on G-code files.
However, PlanetCNC control software can only be used with the USB Mk3 or Mk 4 controllers sold by PlanetCNC.
PlanetCNC software connects to its controller via a USB cable, unlike the LinuxCNC software.
It can perform CAM software functions and can convert NC Drill (Excellon) files, DXF, Gerber files, and PLT/HPGL files into G-code.
In addition, you can edit the G-code as needed using PlanetCNC control software.
PlanetCNC control software is an offline software, and you can install it on 64 and 32 bit Windows, macOS(High Sierra or higher), 64 and 32 bit Linux, RaspberryPi 3 and 4 systems.
Best Free G-code Sender Software
A standalone G-code sender does not directly control the machine. Rather it does so via the controller on the machine.
The G-code sending software sends the instructions to the controller, and the controller creates the necessary instructions for controlling the CNC machine.
Quick summary of UGS software
UGS is a free software that can run on Windows, macOS, Linux, or Raspberry Pi systems.
If you have an Arduino-based CNC machine, UGS combined with GRBL is the most popular software solution to run it.
UGS can be downloaded from its Github page for free and comes in two versions, the classic and the platform.
The platform is a more recent version than the classic version and has improved GUI and controller support.
You can import standard G-code from any CAM software and use it to run your machine.
In addition, you can edit the G-code as need using UGS.
It is the most popular choice among the hobbyist crowd due to its capabilities and ease of use.
Quick summary of cncjs software
It is an open-source controller platform that can be used to send G-code to controllers running on GRBL, Marlin, Smoothieware, and Tiny G firmware.
cncjs is the only control software in my knowledge that has such capabilities.
The setup process might require some time and is tricky, but online support will help you with it.
Once installed on your computer, it uses the web browser to provide a graphical user interface.
Even though it uses a web browser, it does not need an internet connection to run. It creates a local server on your computer, and the web browser is used to access the local server.
The local server can communicate to your controller via USB, Bluetooth, or WiFI.
In addition, you can connect your CNC machine to any computer running cncjs and then use any computer or smartphone connected to the same network for controlling the machine.
cncjs is a light software and can be installed and run on any computer or from a Raspberry Pi.
It has a graphical user interface that is quite similar to OpenBuilds CONTROL and is minimalistic in design.
Quick summary of OpenBuilds CONTROL software
OpenBuilds CONTROL is a software program that interprets the G-code file and instructs the GRBL based controller on your CNC machine.
Your machine must be using a GRBL based control board for you to use OpenBuilds CONTROL software.
The best thing about this control software is the clutter-free and well-organized graphical user interface.
It can work with standard G-code files. In addition, you can use it to flash GRBL firmware on your controller.
OpenBuilds CONTROL is a light software and can be run on Windows, macOS, or Linux operating system-based computers.
Best Free Firmware for CNC Controllers
These are software programs that are run only on the controller hardware of the CNC.
The user seldom interacts with the firmware and interaction is done through controller software.
One of the most popular controller firmware for CNC machines is GRBL.
The other firmware options available are Marlin, Tiny G, and Smoothieware.
It is an open-source firmware developed for 8 bit ATmega328 microcontroller-based control boards for CNC machines.
This firmware supports USB interfacing with the computer, which allows you to control the machines with laptops without parallel ports.
The most recent version of GRBL is v1.1.
However, GRBL only supports 3 axis machining, which is the only limitation of this firmware.
If you need a GRBL for 32-bit boards, you can choose GRBL_HAL or GRBL_Esp32 versions of GRBL, which have been developed for 32-bit boards.
It is the most popular software for budget CNC machines and are used by most hobbyists and DIY enthusiasts.
Some well-known CNC brands like Carbide 3D, BobsCNC, OpenBuilds, and Spark Concepts use GRBL as the firmware for their CNC controller boards.
GRBL has a very large online community, and you can find solutions to most problems online quickly.
Best Free CNC Simulation Software
These software programs simulate the path the tool will take while cutting and helps you predict any unwanted cuts or destructive events.
1. NC Viewer
Quick summary of NC Viewer software
It is a web-based free simulation software that you can use to simulate the G-code generated by any CAM software.
NC Viewer is a web-based software program.
Therefore, it does not require any installation and can work on any OS platform as long an internet connection is available.
It can even be used from your smartphone, which is great for quickly checking your G-code.
You can visit their website and input the G-code from your CAM software and run simulations on it.
NC Viewer can simulate 5-axis machining and also supports turning operations on CNC lathes.
However, it cannot predict collisions as setting machine size, or boundaries of the work area is not supported by NC Viewer.
2. CNC Simulator Pro
|CNC Simulator Pro||Yes||Yes||No||Yes|
Quick summary of CNC Simulator Pro
CNC Simulator Pro is simulation software with CAD/CAM capabilities but is best suited for simulation.
You can install and run it on any computer running Windows 7 and above, and it supports a wide range of CNC machines, tools, and controllers.
It is a premium software that has a free version. The functionalities of the free version is limited but can still do a decent job.
Even though it is an offline software, to use the free version, you will need to renew your free license each month through their website.