Short answer

Oracle says JDK 21 updates released through September 2026 are under the No-Fee Terms and Conditions (NFTC). Starting with the October 20, 2026 Critical Patch Update, further Oracle JDK 21 updates are planned under the Java SE OTN license, which does not allow commercial production use without a subscription. Builds you already installed keep the license they were released under.

Oracle JDK 21 is a long-term support release that Oracle has distributed under two licenses in turn. This guide lays out the dates in Oracle's own words, separates what changes from what doesn't, and lists the places where OTN-licensed builds tend to arrive without anyone deciding to install them.

Key facts: Oracle JDK 21 licensing
Under NFTCOracle JDK 21 updates released through September 2026, including 21.0.12.1 (August 18, 2026)25
Planned under OTNOracle JDK 21 updates released after September 2026, starting with the October 20, 2026 CPU14
Expected first OTN build21.0.13 (inferred from Oracle's numbering; not yet published)
Already-installed NFTC buildsKeep their license6
OTN allows without a subscriptionPersonal use, development and testing, Oracle-approved products, Oracle Cloud Infrastructure8
Free ways to stay on Java 21OpenJDK 21 builds such as Temurin15, Corretto, Zulu or Microsoft
Oracle build still under NFTCOracle JDK 25, planned until September 20281

The dates, from Oracle

Oracle's support roadmap says that update releases of Oracle JDK 21 released after September 2026 are planned to be offered under the Java SE OTN license.1 Oracle's Java blog repeated it in August 2026: all JDK 21 updates through and including September 2026 are available under the NFTC, and the change begins with the October 2026 Critical Patch Update.2 The JDK 21 download page carries the same wording.3

Oracle JDK 21 by release date
DateEventLicense
2026-07-21JDK 21.0.12 (July CPU)NFTC · at risk
2026-08-18JDK 21.0.12.1, the latest release when this guide was verified5NFTC · at risk
2026-09-15Oracle Critical Security Patch Update (CSPU)4NFTC if a JDK 21 build ships in September
2026-10-20October Critical Patch Update4OTN (planned)

Oracle names the date, not the version number. Each CPU has raised the JDK 21 update number by one, so the first OTN build is expected to be 21.0.13. Treat that as an inference until Oracle publishes the release notes.

Why some sites say September 16

Some vendors describe the end of free commercial use for Oracle JDK 21 as September 16, 2026, one year after JDK 25 became generally available.13 Oracle's own pages say updates released after September 2026. In practice both point at the same thing: the next JDK 21 update Oracle ships after September is OTN.

What doesn't change

  • Builds you already installed. Oracle's FAQ says you may continue to use releases you have downloaded under the terms of the license under which you downloaded them.6 An Oracle JDK 21 build released under NFTC, which permits commercial and production use,7 doesn't turn into a paid license on October 1.
  • OpenJDK builds. Temurin, Corretto, Zulu, Liberica, the Microsoft Build of OpenJDK, Red Hat's build and Oracle's own GPL builds from jdk.java.net are not under OTN.
  • Oracle JDK 25. Oracle plans NFTC updates for JDK 25 until September 2028.1

The catch with staying on 21.0.12.1

An NFTC build stays free, but it stops receiving security fixes from Oracle under NFTC. Oracle's release notes for 21.0.12.1 point to October 20, 2026 as the next update.5 Staying on it indefinitely trades a license problem for an unpatched runtime.

What does change: where OTN builds come from

The license exposure arrives with the next update, and updates rarely wait for a decision. These are the places to look:

Auto-updaters

The Windows Java Update Scheduler and Oracle's macOS updater offer newer Oracle builds to the user. On a business machine, accepting one installs whatever license that build carries.

Container images with floating tags

Images such as container-registry.oracle.com/java/jdk:21 follow the newest update of the line. After the October CPU, a rebuild pulls an OTN build. Pinned version tags keep the version you pinned.

CI steps and download scripts

actions/setup-java with distribution: oracle and java-version: 21 downloads from Oracle's JDK 21 latest URL. Oracle says those URLs for JDK 21 will stop working in October 2026.12 Scripts that fetch download.oracle.com/java/21/latest/ have the same problem.

Package repositories and golden images

VM templates, configuration management roles and internal package mirrors that track "latest Oracle JDK 21" will carry the first OTN build into every host built from them.

Builds that are already under OTN today

JDK 21 is the newest case, not the first. These Oracle JDK builds are already OTN-licensed:

  • Oracle JDK 8u211 and later, released from April 16, 2019.10
  • Every Oracle JDK 11 release.11
  • Oracle JDK 17.0.13 and later, released from October 15, 2024.9

The OTN license allows personal use, development use, running Oracle-approved products and use on Oracle Cloud Infrastructure. Anything else needs a license from Oracle.8

How to check what a host runs

The release file in each Java home records the version and vendor. Oracle's commercial builds usually add BUILD_TYPE="commercial" and report Java(TM) SE Runtime Environment; OpenJDK builds say OpenJDK Runtime Environment. IMPLEMENTOR="Oracle Corporation" alone is not enough, because Oracle's GPL builds use it too.

Linux: version, vendor and build type of every JDK under /usr/lib/jvm 
$ grep -H -E '^(JAVA_VERSION|IMPLEMENTOR|BUILD_TYPE)=' /usr/lib/jvm/*/release
$ java -version 2>&1 | head -2

Your options

  1. Switch to a free OpenJDK 21 build. Same major version, same bytecode level, usually a package or base-image change. Eclipse Temurin, for example, is distributed without licensing fees.15
  2. Move to Oracle JDK 25 if you want to stay on Oracle builds under NFTC. This is a major-version upgrade, so test accordingly.
  3. Buy a Java SE Universal Subscription. Oracle's FAQ says pricing starts at $15 per employee per month,14 and the price list counts all employees, not only the people who use Java.16
  4. Pin to 21.0.12.1 only as a short bridge while you migrate, because it gets no further NFTC security fixes.

For CI specifically, see setup-java with distribution: oracle. For the vocabulary, see the glossary.

How RuntimeClear helps

The free RuntimeClear scanner finds Oracle JDK 21 installs and the references that would pull the next update: enabled auto-updaters, floating :21 image tags, setup-java steps and download.oracle.com/java/21/latest URLs. The report tool marks them at risk and shows counts for free; the paid report adds the replacement commands for each platform.

This guide is a summary to help you plan, not legal advice. Your agreements with Oracle decide what applies to you.

Questions

Is Java 21 still free?

OpenJDK 21 builds from vendors such as Eclipse Temurin, Amazon Corretto, Azul Zulu, Microsoft and Red Hat stay free. Oracle JDK 21 builds released through September 2026 are under NFTC. Oracle JDK 21 updates released after that are planned under OTN.

Do I need a subscription for development and testing?

The OTN license permits use to develop, test, prototype and demonstrate your applications. Commercial production use is what needs a Java SE subscription. CI build jobs usually count as development; production images and servers do not.

Is Oracle JDK 25 a free alternative?

Oracle JDK 25 is under NFTC, and Oracle plans NFTC updates for it until September 2028. Moving to it keeps you on Oracle builds without a subscription for now, but it is a major-version upgrade and the same change is planned for 2028.

Which version will be the first OTN build of JDK 21?

Oracle names the date, October 20, 2026, not the version. Each Critical Patch Update has raised the update number by one, so 21.0.13 is expected, but treat that as an inference until Oracle publishes the release notes.

Does my Oracle JDK 21.0.12 install become paid on October 1?

No. A build keeps the license it was released under. The exposure comes from installing a newer Oracle JDK 21 update after the October 2026 CPU, which usually happens through auto-updaters, floating image tags or CI steps.

Sources

  1. Oracle Java SE Support Roadmap Checked 2026-09-11.
  2. Oracle Java blog: JDK 21 approaches end of permissive license (Aug 14, 2026) Checked 2026-09-11.
  3. Oracle Java Downloads, JDK 21JDK 21 will receive updates under the NFTC, until September 2026 … Subsequent JDK 21 updates will be licensed under the Java SE OTN License. Checked 2026-09-11.
  4. Oracle Critical Security Patch Update, August 2026 (upcoming patch dates) Checked 2026-09-11.
  5. JDK 21.0.12.1 release notes (Aug 18, 2026) Checked 2026-09-11.
  6. Oracle JDK License General FAQsYou may continue to use releases you have downloaded under the terms of the license under which you downloaded them. Checked 2026-09-11.
  7. Oracle No-Fee Terms and Conditions (NFTC) Checked 2026-09-11.
  8. Oracle Technology Network License Agreement for Oracle Java SE Checked 2026-09-11.
  9. JDK 17.0.13 release notes: first JDK 17 update under OTN (Oct 15, 2024) Checked 2026-09-11.
  10. Oracle Java SE 8 archive: 8u211 and later (OTN) Checked 2026-09-11.
  11. JDK 11 release notes: Oracle JDK under OTN Checked 2026-09-11.
  12. Oracle JDK script-friendly download URLs Checked 2026-09-11.
  13. Azul: Java 21 end of free commercial use FAQ Checked 2026-09-11.
  14. Oracle Java SE Universal Subscription FAQ Checked 2026-09-11.
  15. Eclipse Adoptium: Temurin Checked 2026-09-11.
  16. Oracle Java SE Universal Subscription global price list (PDF) Checked 2026-09-11.