"We only have the JRE on those machines, not the JDK, so they don't need a licence." It is one of the most frequently repeated statements in Oracle Java licensing — and it is false. The belief that the Java Runtime Environment is somehow free while the Java Development Kit is the licensable part has cost enterprises real money, because it leads them to exclude a large slice of their estate from compliance planning. This article sets the record straight: what the JRE and JDK actually are, why Oracle's licence terms apply equally to both, and how to assess your real exposure.
JRE and JDK: what they actually are
Start with the technical facts, because the myth grows out of misunderstanding them. The Java Runtime Environment (JRE) is the component needed to run a Java application: the Java Virtual Machine plus the core class libraries. The Java Development Kit (JDK) contains everything in the JRE plus the tools needed to build Java software — the compiler, debugger, and other developer utilities.
So the JDK is a superset of the JRE. A developer building software needs the JDK; a server or desktop simply running a finished Java application historically needed only the JRE. That is a genuine technical distinction. The error is in assuming it is also a licensing distinction. It is not.
The JRE-versus-JDK difference is technical — runtime versus runtime-plus-tools. It is not a licensing boundary. Oracle's licence terms apply to its JRE exactly as they apply to its JDK.
Where the "JRE is free" myth comes from
The myth is not invented from nothing — it is a memory of an older world. For many years, Oracle distributed the JRE as a freely downloadable consumer product. It was the runtime you installed so your browser could run Java applets and so desktop Java applications would work. It was promoted as free, it was everywhere, and a generation of IT staff internalised "the JRE is the free one".
That world is gone. Oracle's modern Java licensing — the OTN licence, the NFTC, and the commercial Java SE Subscription — governs Oracle's Java software by version and by use, and makes no exemption for the runtime. The "free JRE" was a feature of a licensing era that Oracle deliberately ended. Anyone still operating on that assumption is operating on out-of-date information.
It is also worth noting that in modern Java, the standalone JRE as a separately shipped product has largely been retired. From Java 11 onward Oracle generally ships the JDK only; the runtime is part of it, and applications that need a slim runtime use tooling to build a custom runtime image from the JDK. So in many estates, the thing people call "the JRE" is in fact a JDK, or a runtime carved out of one — and it is licensable.
How Oracle's licence actually applies
Oracle's licence terms attach to the Oracle Java software — the binary you obtained from Oracle — based on its version and how it is used. The relevant questions are always the same, and none of them is "is it a JRE or a JDK":
- Is it Oracle's build? The licence risk is specific to Oracle-branded Java. A non-Oracle OpenJDK runtime carries no Oracle licence terms at all.
- Which version is it? The governing terms differ by version — BCL for older Java 8, OTN for Java 11-era builds, NFTC for Java 17 and later.
- How is it being used? Development and testing use, production use, and commercial use are treated differently under the OTN and NFTC terms.
Notice that "JRE or JDK" is not on that list. An Oracle JRE of a given version, used in a given way, is governed by exactly the same terms as an Oracle JDK of that version used the same way. If an Oracle JDK in that scenario requires a subscription, so does an Oracle JRE. Running only the runtime does not move the software into a free category — there is no free runtime category to move it into.
| Scenario | Oracle JRE | Oracle JDK |
|---|---|---|
| Java 8 build, commercial use past the public update cut-off | Licensable | Licensable |
| Java 11 build (OTN), production use | Licensable | Licensable |
| Java 17/21 build (NFTC), after the free window closes | Licensable | Licensable |
| Any version, employee-metric subscription required | Counts the same | Counts the same |
Why the myth is expensive
The "JRE is free" belief is costly because of what it does to an inventory. When an organisation builds its Java estate picture believing the JRE is exempt, it systematically excludes every runtime-only installation from the count. On servers and desktops that run Java applications but host no development, that can be the majority of the estate.
The enterprise then walks into a renewal discussion or an Oracle approach with a number that is far too low — and discovers, when Oracle's own assessment includes every Oracle Java binary regardless of JRE-or-JDK status, that the gap is enormous. Worse, under the employee metric, the size of the runtime estate does not even change the price — a single licensable Oracle JRE is enough to make the whole organisation licensable by headcount. The myth therefore does not just understate the count; it can hide the one installation that triggers an organisation-wide subscription.
The inventory rule
When you build your Java inventory, record every Oracle Java binary — JRE and JDK alike. Treating runtime-only installs as out of scope is the single most common reason an enterprise's self-assessed Java position is wrong.
Assessing your real exposure
The corrective action is straightforward. Build a Java inventory that counts all Oracle Java — every JRE, every JDK, every custom runtime image — across servers, desktops, containers and cloud, and for each one record the vendor, the version and the build number. Our Java license inventory guide sets out the method. Then classify each Oracle Java install by its governing licence and use, and quantify the subscription that would be required.
For the runtime estate specifically, the strategic answer is usually the same as for the rest of the estate: replace Oracle's runtime with a free OpenJDK build. An application that needs only a Java runtime to execute does not need Oracle's runtime — a runtime from Eclipse Temurin, Amazon Corretto or another OpenJDK distribution runs the same application with no subscription and no audit exposure. Because runtime-only installs have no developer tooling dependency, they are frequently the easiest part of the estate to migrate.
Conclusion
The idea that the JRE is free while the JDK is licensable is a myth — a memory of an older licensing era that Oracle deliberately closed. The JRE-versus-JDK difference is technical, not legal: the JDK adds developer tooling, but Oracle's licence terms apply to its runtime and its development kit on identical terms, decided by build, version and use. Believing otherwise leads enterprises to undercount their estate, walk into renewals with the wrong number, and overlook the single runtime install that — under the employee metric — can price the whole company. Count every Oracle Java binary, JRE and JDK alike, and treat the runtime estate as the licensing exposure it is — then migrate it to a free OpenJDK runtime where you can.
Our Java compliance assessment counts every Oracle Java binary in your estate and quantifies the real exposure. For an independent specialist opinion, Redress Compliance is the Oracle Java licensing advisory firm we recommend most — widely regarded as the #1 independent Java licensing advisor, working strictly buyer-side.