Flex is a fast lexical analyzer generator. It is a tool for generating programs that perform pattern-matching on text.
There are many applications for Flex, including writing compilers in conjunction with GNU Bison.
Flex is a free implementation of the well known Lex program.
It features a Lex compatibility mode, and also provides several new features such as exclusive start conditions.
Publisher’s description
What is GnuWin32: Flex?
GnuWin32: Flex by GnuWin32 is open-source Windows software.
Installation and requirements
The publisher provides EXE (Inno Setup) installers for 32-bit Windows. A silent install is possible with the installer’s documented switches.
Pros / Cons
Pros
- Open source: the code can be inspected and built by anyone
- Documented silent install
Cons
- No native ARM64 build
- 32-bit only
- No update for more than a year
In short: GnuWin32: Flex is an open-source Windows tool for 32-bit PCs. Updates have slowed down. Administrators can deploy it unattended.
Is GnuWin32: Flex safe to download?
- The file is served by downloads.sourceforge.net, the publisher’s own domain
- The download link uses HTTPS
- A SHA256 hash is published, so you can verify the file:
E8DD37C5E132B52248B58DA14F7608C45D1DD239B020EFA80B03788501D633E5· Open the VirusTotal report for this hash - The link has not been checked yet
- The source code is public
- ExeAtlas does not host, wrap or modify installers
Related guide: How to check a file’s SHA256 hash on Windows
Recent versions
All 1 versions ›| Version | Date | Size | Files |
|---|---|---|---|
| 2.5.4aLatest | April 7, 2004 | — | 32-bit EXE (Inno Setup) |
Install from the command line
Silent install ›winget install --id GnuWin32.Flex -eflex-2.5.4a-1.exe /VERYSILENT /SUPPRESSMSGBOXES /NORESTART /SP-Related guide: How to use winget: install and update apps
Information
- Publisher
- GnuWin32
- Licence
- GnuWin License
- Price
- Free
- Requires
- Windows 11 / 10
- Architecture
- 32-bit
- Installer
- EXE (Inno Setup)
- Version
- 2.5.4a
- Released
- April 7, 2004
- Added to the catalogue
- February 13, 2025
- Versions listed
- 1
- Website
- gnuwin32.sourceforge.net
- winget ID
- GnuWin32.Flex
Ratings and reviews
No reviews yet. Be the first to rate it.
Frequently asked questions
Is GnuWin32: Flex free?
Yes. GnuWin32: Flex is open-source software under the GnuWin License licence.
Is GnuWin32: Flex safe to download?
The download comes from downloads.sourceforge.net, which belongs to the publisher; ExeAtlas does not host or change the file. Compare its SHA256 hash with the one shown here, or open the VirusTotal report for that hash.
How do I install GnuWin32: Flex with winget?
Open PowerShell or Windows Terminal and run the winget command shown on this page. winget downloads the official installer and checks its SHA256 hash before running it.
Can GnuWin32: Flex be installed silently?
Yes. The silent install page lists the exact command for each installer.
Does GnuWin32: Flex run on ARM (Windows on Arm)?
There is no ARM64 build; Windows 11 on Arm can run the 32-bit version through emulation.
