Open files in VS Code and Cursor / Binary, network and hardware

View VCD waveforms in VS Code

Install the free VCD Viewer & Waveform Viewer by Zovo and click the .vcd file your testbench wrote. The waves open in a VS Code tab with a signal tree, a value column at the cursor, markers A and B with the time between them, buses and hex, binary, signed or ASCII radix. You can show as many signals as you like, and a 1 GB file shows its first waves in seconds.

Free, MIT license. Extension ID zovo.zovo-vcd-waveform-viewer, version 0.2.2. Needs VS Code 1.90.0 or newer.

Steps in VS Code

1. Install VCD Viewer from the Marketplace, or press Ctrl+P (Cmd+P on macOS) and run ext install zovo.zovo-vcd-waveform-viewer.
2. In your testbench, dump a VCD: $dumpfile("wave.vcd"); $dumpvars(0, tb); in Verilog, --vcd=wave.vcd for GHDL or --trace for Verilator.
3. Click the .vcd file. The first 64 signals show at once. If another viewer opens it, right-click and pick "Open in VCD Waveform Viewer".
4. Double-click a signal in the tree to add it, or press + next to a scope to add all of its signals.
5. Ctrl or Cmd + wheel zooms at the mouse. Press A and B to place markers, and the arrow keys to jump between changes.

Steps in Cursor, Windsurf or VSCodium

1. Open the Extensions view with Ctrl+Shift+X (Cmd+Shift+X on macOS).
2. Search for zovo.zovo-vcd-waveform-viewer and click Install. Cursor, Windsurf and VSCodium install from Open VSX, where it is published as zovo/zovo-vcd-waveform-viewer.
3. If your editor has no gallery, download the .vsix from the Open VSX page and run "Extensions: Install from VSIX...".
4. Then use it the same way as in VS Code.

What VCD Viewer handles

• VCD from Icarus Verilog, Verilator, Vivado, ModelSim and GHDL, including x, z and VHDL values such as U, W, L and H.
• No signal limit. A 1.07 GB file with 20,000 signals showed its first waves after 4.3 s in a real VS Code.
• Your signal list, radixes, names, zoom and markers are kept per file and come back when the simulator writes the file again.
• Damaged files open with a note: a cut-off file, time going backwards, or a signal declared twice.

What it does not do

• VCD only. FST, GHW and LXT files are not read yet.
• Real values are drawn as values in a bus shape, not as an analog curve.
• GTKWave .gtkw save files are not read. Use Export and Import for signal lists.

In JetBrains IDEs (IntelliJ IDEA, PyCharm, WebStorm, CLion and others)

• SystemVerilog Studio. Zovo has no JetBrains plugin for VCD files, and we found no VCD waveform viewer on the JetBrains Marketplace on 9 November 2026. SystemVerilog Studio (13,047 downloads) is a SystemVerilog and Verilog editor, not a waveform viewer.
• GTKWave. Open the VCD in GTKWave or Surfer next to the IDE.

Other options

• VaporView (lramseyer.vaporview, 24,959 installs, on Open VSX). Its own description: "Waveform Viewer for VS code - Supports VCD, FST, and GHW formats". Use it if your simulator writes FST or GHW.
• WaveTrace (wavetrace.wavetrace, 98,552 installs, not on Open VSX). Its own description: "Interactive VCD waveform viewer for FPGA/RTL developers". Not on Open VSX.
• GTKWave. The long-standing free desktop waveform viewer. It reads VCD, FST and LXT and has its own save files.
• Surfer. A free, open source waveform viewer that runs on the desktop and in a browser.

Install counts and Open VSX status were checked on 9 November 2026. Descriptions in quotes are the extensions' own.

Questions

More about VCD Viewer

Read the VCD Viewer page for every feature and setting, or the source code on GitHub.

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