What actually changes between Amazon Linux 2 and Amazon Linux 2023 — and why it matters now: AL2 reaches end of life 2026-06-30 (no more patches or AMIs), so AL2023 isn't optional. Facts below are from AWS's own AL2-vs-AL2023 comparison.
| Area | Amazon Linux 2 | Amazon Linux 2023 |
|---|---|---|
| Package manager | yum | dnf (a yum symlink remains for compatibility) |
| Extras library | amazon-linux-extras | Removed — packages are default, version-namespaced (python3.11, nginx1.24), or in SPAL |
| Time sync | ntpd | chronyd |
| Firewall backend | iptables | nftables |
| Python | 2.7 and 3.x | 3.x only — no Python 2 |
| glibc | 2.26 | 2.34 |
| Releases & support | Single rolling release | Versioned releases, 5-year support, quarterly updates, deterministic upgrades |
| Security defaults | Looser | Hardened — SELinux on, IMDSv2-friendly, locked-down by default |
[AWS source: comparing AL2 and AL2023]
Scan your stack free — find your AL2 usage →
The breaking changes above each have a known fix. See the step-by-step AL2 → AL2023 checklist and the migration guide, or get a hash-anchored audit ($299, 30-day money-back) that finds every AL2 reference and scores it.