---
name: "vcd2fst"
section: "1"
platform: "linux"
package: "gtkwave"
version: "3.3.128-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/vcd2fst"
---

# vcd2fst(1)

Converts VCD files to FST files

## NAME

vcd2fst - Converts VCD files to FST files

## SYNTAX

vcd2fst \[*option*\]... \[*VCDFILE*\] \[*FSTFILE*\]

## DESCRIPTION

Converts VCD files to FST files.

## OPTIONS

- **-v,--vcdname** \<*filename*\>

  Specify VCD/FSDB/VPD/WLF input filename.  Processing of filetypes other than VCD requires that the appropriate 2vcd converter was found during ./configure.

- **-f,--fstname** \<*filename*\>

  Specify FST output filename.

- **-4,--fourpack**

  Indicates that LZ4 should be used for value change data (default).

- **-F,--fastpack**

  Indicates that fastlz should be used instead of LZ4 for value change data.

- **-Z,--zlibpack**

  Indicates that zlib should be used instead of LZ4 for value change data.

- **-c,--compress**

  Indicates that the entire file should be run through gzip on close.  This results in much smaller files at the expense of a one-time decompression penalty on file open during reads.

- **-p,--parallel**

  Indicates that parallel mode should be enabled.  This spawns a worker thread to continue with FST block processing while conversion continues on the main thread for new FST block data.

- **-h,--help**

  Show help screen.

- Note that you should specify dumpfile.vcd directly or use "-" for stdin.

  ## EXAMPLES

- vcd2fst dumpfile.vcd dumpfile.fst --compress

  This indicates that the FST file should be post-compressed on close.

## AUTHORS

Anthony Bybell \<bybell@rocketmail.com\>

## SEE ALSO

[*fst2vcd*(1)](/fst2vcd/1.md) [*vcd2lxt*(1)](/vcd2lxt/1.md) [*vcd2lxt2*(1)](/vcd2lxt2/1.md) [*lxt2vcd*(1)](/lxt2vcd/1.md) [*vcd2vzt*(1)](/vcd2vzt/1.md) [*vzt2vcd*(1)](/vzt2vcd/1.md) [*gtkwave*(1)](/gtkwave/1.md)