AlmaLinux vs Rocky Linux: differences, support and which to choose

Short answer: AlmaLinux and Rocky Linux are both free rebuilds of Red Hat Enterprise Linux with the same packages and support dates (security fixes for version 9 until 31 May 2032). Rocky aims to be bug-for-bug compatible with RHEL; AlmaLinux aims for binary compatibility and adds extras, such as version 10 builds for older CPUs. Either suits most servers.

Versions, dates and policy statements below are as of October 2026, taken from almalinux.org, the AlmaLinux wiki, rockylinux.org and the Rocky Linux documentation. The CPU check further down was run on Debian 12 with glibc 2.36; nothing here was run on an AlmaLinux or Rocky machine for this article.

AlmaLinux vs Rocky Linux at a glance

Why there are two: the end of CentOS Linux

For years CentOS Linux was the free, rebuilt copy of RHEL that many hosting servers ran. In December 2020 Red Hat announced that CentOS Linux 8 would end in 2021 and that CentOS would continue only as CentOS Stream, the development branch that sits just ahead of the next RHEL minor release rather than behind it. CentOS Linux 7 followed in June 2024. Two projects formed in 2021 to keep a free rebuild going: AlmaLinux, started by CloudLinux and handed to a foundation, and Rocky Linux, started by Gregory Kurtzer, one of CentOS’s co-founders. Both shipped their first stable releases that year and have tracked every RHEL release since.

Governance: who controls each project

The AlmaLinux OS Foundation describes itself as a 501(c)(6) non-profit that stewards the project. The community elects the board, and the minutes of every board meeting are published within 14 days.

The Rocky Enterprise Software Foundation is a public benefit corporation registered in Delaware, set up by Gregory Kurtzer. Its rules say board seats are never sold and no single company may hold more than a third of the voting board. CIQ, Kurtzer’s company, is one of Rocky’s sponsors and sells commercial support for it.

Both models are designed to stop any one company from taking the distribution away again, which is the risk the CentOS change made obvious. Neither affects what you run day to day.

How each one gets RHEL’s source code after 2023

In June 2023 Red Hat stopped publishing RHEL’s source packages on git.centos.org; public sources now come from CentOS Stream, and the exact RHEL sources only reach customers under their subscription terms. The two projects reacted differently:

• AlmaLinux announced on 13 July 2023 that it would drop the aim to be 1:1 with RHEL and aim for binary compatibility instead: software and kernel modules built for RHEL should run unchanged, but AlmaLinux no longer has to copy every RHEL bug and may ship a fix before Red Hat does. It builds from CentOS Stream and asks bug reporters to check whether a problem also appears there.
• Rocky Linux published on 29 June 2023 how it keeps rebuilding the exact RHEL sources: from Red Hat’s freely available UBI container images and from pay-per-use RHEL cloud instances, plus CentOS Stream and upstream projects. Its homepage still describes Rocky as designed to be 100% bug-for-bug compatible with RHEL.

In practice, an application built for RHEL 9 runs on both. The difference shows only in edge cases: on AlmaLinux a package can carry a fix that RHEL does not have yet; on Rocky the goal is that the package behaves exactly like RHEL’s, bugs included. If your vendor’s support contract names one rebuild specifically, that settles it.

Version 10: where they visibly differ

RHEL 10 and Rocky Linux 10 are built for the x86-64-v3 microarchitecture level, which needs AVX2 and related instructions (Intel Haswell or newer). On an older CPU, or in a virtual machine whose virtual CPU does not pass those instructions through, they will not run. AlmaLinux 10 follows RHEL with x86-64-v3 by default but also publishes a separate x86_64_v2 build, with EPEL packages built for it, so older hardware keeps getting updates. Its version 10 release also turns on frame pointers for profiling, re-enables SPICE and restores support for more than 150 devices that RHEL dropped.

Check what your machine supports before you pick version 10. The dynamic loader lists the levels the CPU supports; the output below is from Debian 12 with glibc 2.36, and the same option works on any EL9 system (glibc 2.34):

/lib64/ld-linux-x86-64.so.2 --help | grep x86-64-v

  x86-64-v4 (supported, searched)
  x86-64-v3 (supported, searched)
  x86-64-v2 (supported, searched)

If the x86-64-v3 line does not say supported, stay on version 9 or use AlmaLinux’s x86_64_v2 build. In a VM, run the check inside the guest: what counts is the CPU model the hypervisor presents, not the host’s spec sheet.

Release timing

Both rebuild each RHEL minor release after Red Hat publishes it. AlmaLinux has usually been first, by a day to about two weeks:

Dates are from the AlmaLinux wiki’s release notes and from Rocky Linux’s release table and announcements. For a server this gap rarely matters: security updates for the current minor release flow continuously on both, and only the latest minor release of each major version is supported. A plain sudo dnf upgrade moves you from 9.7 to 9.8 when it appears; there is no separate step.

Support windows

Because both follow RHEL’s schedule, their dates are identical. Version 8 gets security fixes until 31 May 2029, version 9 until 31 May 2032 and version 10 until 31 May 2035. Active support, meaning new hardware enablement and non-security fixes, ends five years earlier: 31 May 2027 for version 9 and 31 May 2030 for version 10. On either distribution, a server installed with version 9 today can run without a major upgrade for more than five years.

Moving between them, and upgrading

Since both are RHEL-compatible, each project offers a script that converts an existing Enterprise Linux install in place, keeping its configuration and packages:

curl -O https://raw.githubusercontent.com/AlmaLinux/almalinux-deploy/master/almalinux-deploy.sh
sudo bash almalinux-deploy.sh

curl -O https://raw.githubusercontent.com/rocky-linux/rocky-tools/main/migrate2rocky/migrate2rocky9.sh
sudo bash migrate2rocky9.sh -r

Major upgrades are where the two differ most. AlmaLinux maintains ELevate, built on Red Hat’s Leapp framework, which upgrades in place from 8 to 9 and from 9 to 10 within the same distribution, and takes old CentOS 7 machines to AlmaLinux 8. ELevate stopped supporting Rocky Linux with its update of 3 November 2025. Rocky’s own documentation does not support in-place major upgrades at all and recommends a fresh install of the new version. If you expect to stay on one install across versions 9 and 10, that alone can tip the choice to AlmaLinux.

To see which one a machine runs today, cat /etc/os-release shows ID="almalinux" or ID="rocky", and checking the Linux version covers the other ways. Both use dnf; yum still works as an alias, and yum: command not found explains what to do where it does not.

AlmaLinux or Rocky Linux on a VPS

On a VPS the choice is often made by the template list. VMHeaven’s Linux VPS offers Rocky Linux 9 (alongside Ubuntu, Debian and CentOS Stream) at order time and as a reinstall from the panel; there is no AlmaLinux template. That leaves two routes:

• Run Rocky Linux 9. Same packages, same tools, same support date of 31 May 2032. For most workloads there is nothing to gain from switching.
• Convert to AlmaLinux 9. The almalinux-deploy README lists Rocky Linux 9 as a supported source, so a fresh Rocky install can be converted with the commands above. Take a backup from the panel first. We have not run the conversion on our templates ourselves, so treat the first run as a test on a fresh server, not on one that already holds data.

If you are not tied to the Red Hat family at all, a Debian or Ubuntu server is the more common choice for web stacks and Docker hosts; see Debian vs Ubuntu for that comparison.

How to choose

• Your software vendor certifies or supports one by name: use that one.
• You want behaviour identical to RHEL, bugs included: Rocky Linux.
• You want in-place upgrades from 9 to 10 later: AlmaLinux, through ELevate.
• Your hardware or VM lacks x86-64-v3 and you want version 10: AlmaLinux’s x86_64_v2 build.
• Your provider offers only one as a template: take it. The two are close enough that this is a perfectly good reason.

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