How to Install Icarus Verilog on Windows, macOS, and Linux (2026 Guide)

First, A Reality Check

You don't need to install anything to learn Verilog. Every interactive editor in these docs runs real Verilog through Icarus Verilog in a sandbox, including the waveform viewer. If you're here to learn the language, skip this page and come back when you want to work on a longer project locally.

Still want a local install? Read on.

What "Installing Verilog" Actually Means

Verilog is a language, not a program. To run it you need:

1. A simulator - the tool that compiles your .v files and runs them. For most learners that's Icarus Verilog, which gives you the iverilog compiler and the vvp runtime.
2. A waveform viewer - usually GTKWave - that reads the .vcd files your testbench produces.
3. A text editor - VS Code with a Verilog extension is the common pick, but anything works.

Vendor toolchains (Xilinx Vivado, Intel Quartus, Synopsys VCS, Cadence Xcelium) exist for FPGA programming and ASIC work. They're large, often licensed, and overkill for learning. Stick with Icarus.

Installing on macOS

The fastest path is Homebrew:

brew install icarus-verilog gtkwave

That installs both the compiler and the waveform viewer. Verify:

iverilog -V
gtkwave --version

You should see version numbers from both. iverilog puts itself on your PATH automatically. GTKWave installs an app bundle under /Applications and a gtkwave command line you can launch from the terminal.

If Homebrew isn't installed, follow the instructions at brew.sh first - it's one curl command - then come back.

Installing on Linux

On Debian-based distributions (Ubuntu, Mint, Pop!_OS):

sudo apt update
sudo apt install iverilog gtkwave

On Fedora / RHEL-style systems:

sudo dnf install iverilog gtkwave

On Arch:

sudo pacman -S iverilog gtkwave

Then verify the same way:

iverilog -V
gtkwave --version

The packaged version sometimes lags upstream by a release. For most learning that's fine. If you need a newer release, build from source - the project's GitHub repo has instructions, and it's a ./configure && make && sudo make install away.

Installing on Windows

The easiest route is the prebuilt installer maintained by the iverilog community at bleyer.org (search for "iverilog Windows"). It bundles Icarus Verilog, GTKWave, and the GCC toolchain Icarus needs internally.

1. Download the latest installer (typically iverilog-vXX-setup.exe).
2. Run it. Accept the defaults unless you have a reason not to.
3. When the installer asks, leave "Add to PATH" checked.
4. Open a new PowerShell or Command Prompt window and verify:

iverilog -V
gtkwave --version

If you forgot to add to PATH, the binary lives at something like C:\iverilog\bin\iverilog.exe. Either add C:\iverilog\bin to your user PATH from System Properties, or re-run the installer and tick the box.

WSL2 is also a fine option on Windows - install Ubuntu from the Microsoft Store and follow the Linux instructions inside it. You'll have a more familiar Unix-y workflow.

Compiling and Running Your First File

Once installed, the workflow looks like this. Save a file as hello.v:

module hello;
    initial begin
        $display("hello from verilog");
        $finish;
    end
endmodule

Compile it into a simulation binary:

iverilog -o hello hello.v

iverilog is the compiler. -o hello names the output. hello.v is your source.

Run the simulation:

vvp hello

You should see:

hello from verilog

That's the entire local loop. From here you can split your design across multiple files (iverilog -o sim *.v), use the -g2012 flag to enable SystemVerilog-2012 features, or pipe the output to your own scripts.

Producing and Viewing a Waveform

Add $dumpfile and $dumpvars to your testbench, run it, and open the resulting VCD in GTKWave:

initial begin
    $dumpfile("dump.vcd");
    $dumpvars(0, test);
    // ...
end

After vvp sim finishes, you'll have a dump.vcd next to your source. Open it:

gtkwave dump.vcd

GTKWave loads the file and presents the signal tree on the left. Drag the signals you care about into the wave area on the right. We cover this in detail in Dumpfile and VCD.

Common Errors

iverilog: command not found - the binary isn't on your PATH. On Windows that usually means the installer wasn't run with PATH update enabled. On macOS/Linux it usually means Homebrew/apt didn't finish, or you're in a shell that hasn't reloaded its PATH (close and reopen the terminal).

syntax error on a line that looks correct - check that you're not using a SystemVerilog feature in plain Verilog mode. Pass -g2012 to iverilog to enable SystemVerilog-2012:

iverilog -g2012 -o sim main.v

Unknown module during compile - either the module's source file wasn't passed to iverilog, or the module name in the instantiation doesn't match the module declaration exactly. Verilog is case-sensitive.

Empty waveform in GTKWave - your testbench didn't call $dumpfile and $dumpvars, or the simulation hit $finish before any signals changed. Add at least one $dumpvars(0, top) and let the simulation run long enough for transitions.

What Comes Next

Whether you installed locally or stuck with the browser, the next doc walks through writing your first complete module from scratch - module declaration, ports, a tiny piece of combinational logic, and a testbench around it.