For twenty-eight years, the OpenSSL Library has shipped one way: as source code. If you were on Windows, you built it yourself, or you trusted a binary someone else built. That changes now. We have published the first officially produced binary distribution of the OpenSSL Library: a Windows installer, released for testing on GitHub on 11 August 2026.
Let's be clear about what this is: a testing release. It covers version 4.0.1 of the Library and ships as six release assets. The stable installer arrives with the 4.1 release, and what happens between now and then depends, in part, on you.
Source only
The Library ships as source code. Windows users build it themselves or rely on third-party binaries.
Testing release
The first officially produced binary distribution: a Windows installer for Library version 4.0.1.
Stable installer
The stable version of the installer ships starting with the 4.1 release of the OpenSSL Library.
What you get.
Three things, cleanly packaged:
The Library DLLs
The OpenSSL Library itself, as Windows DLLs, ready to link against.
openssl.exe
The command-line application, installed and on your PATH if you want it.
The development kit
Everything needed to build applications against the Library: headers, libs, PDBs, and documentation.
Every piece of it, from the installer to the application to every installed DLL, is digitally signed with the OpenSSL Corporation key, verifiable through the standard Windows code-signing mechanisms. You know exactly what you're running, and exactly who built it. Minimum supported platforms are Windows 7 and Windows Server 2008 R2, x64 only.
Why x64 only? Because this is a testing release, we decided to start with the x64 architecture. If you need an Arm64 build for Windows, send us a note on the issue tracker. We are not promising it for 4.1; it takes real engineering effort and hardware. But knowing people want it is exactly the kind of feedback this phase is for.
One key signs the whole chain; Windows code-signing verifies each piece.
Two variants, two formats.
There are two variants. One bundles the Microsoft Visual Studio redistributable. The other is a Hybrid CRT build with no redistributable dependency at all. Both come in EXE and MSI formats. Take your pick.
Naming as on the releases page: OpenSSL-x64-VS-<version> and OpenSSL-x64-hybridCRT-<version>.
Which one is for you? Norbert Pócs, the engineer behind the installer, puts it the way an engineer would:
"If they don't know what the difference is, it doesn't really matter which one they install. If they know what the difference is, they will know which one they want."
Optional FIPS provider.
If you need FIPS, the installer has you covered. Choose between the FIPS-validated module and the current-version module, and the installer hooks it into the configuration for you, so the command line works with FIPS out of the box. No manual wiring.
The validated module
The FIPS-validated OpenSSL FIPS provider version. Ships with the Visual Studio redistributable variant.
The current module
The FIPS provider that comes with the current Library version. Available in both variants.
The FIPS provider needs openssl.exe installed alongside it; the application generates the fipsmodule.cnf configuration.
Why a testing release.
Because we would rather find out now what Windows users actually need than guess and find out later. In Norbert's words:
"It is very hard to know what customers actually need. Not what they want, but what they actually need. We want to start with: this is the thing we think is good for you. Now we want feedback to see if we got it right."
So here is the invitation: install it, and tell us what happens. Installation behaviour, packaging, signing, toolchain integration, and most of all the reports we did not think to ask for. File them on the openssl/installer issue tracker. Every one gets read by the people who built this.
Try it.
The testing release is on the releases page now. The README covers the details, and the announcement on OpenSSL Communities is the canonical source text. Twenty-eight years of source-only distribution, one download away from being history. Come and tell us if we got it right.
Break it before we call it stable.
Download the installer, run it across your Windows estate, and file what you find. The stable installer ships with OpenSSL 4.1, shaped by what you report.
Written by Magdalena Zdunkiewicz. Field Reports: dispatches from OpenSSL Corporation on the work at the intersection of cryptography, open source, and the community.