What Azul Zulu is
Azul Zulu is a certified, OpenJDK based Java distribution produced by Azul, a company whose entire business is Java runtimes. It comes in two forms that buyers should keep distinct. Zulu Community is a free build, comparable in spirit to Amazon Corretto, suitable for production and patched on the OpenJDK cadence. Azul Platform Core is the commercial product, adding a formal support contract, extended version coverage, and service level commitments. This article sits beneath the Oracle Java licensing pillar and extends the OpenJDK versus Oracle JDK comparison.
For licensing purposes, what matters is that neither form is Oracle's commercially licensed JDK, so running Zulu creates no Java SE Universal Subscription obligation. The free build costs nothing; the commercial product carries an Azul fee, but that fee buys support, not the right to run Java, and it is structured very differently from Oracle's workforce based subscription.
Free build versus Platform Core
The choice between the free Zulu build and Azul Platform Core is a support decision, not a licensing one, because both are free of any Oracle obligation. Organisations that are comfortable consuming public security updates and handling their own Java operations can run the free build at no cost. Organisations that want a vendor on the hook, with guaranteed response times, longer support horizons for older Java versions, and indemnification, buy Platform Core.
With Azul the question is not whether to pay Oracle. It is whether to pay anyone, and if so, for support rather than for permission.
This is the meaningful difference from Amazon Corretto, which offers free builds and support largely through the AWS platform. Azul sells support as a standalone product to customers on any infrastructure, which appeals to regulated enterprises that require a contracted support relationship for production runtimes. The alternative free option is covered in the Amazon Corretto comparison.
The cost comparison
The contrast with Oracle is structural. Oracle's employee subscription scales with your headcount and is unavoidable once you use Oracle JDK. Azul's commercial pricing is tied to the Java estate you actually want supported, typically by core or by deployment, which means it scales with usage rather than with the size of your organisation. For an enterprise with a large workforce but a modest Java footprint, that difference alone can be decisive.
| Dimension | Azul Zulu | Oracle Java |
|---|---|---|
| Free build available | Yes | Limited, no fee terms only |
| Commercial pricing basis | Java estate, by usage | Total workforce |
| Source base | OpenJDK | OpenJDK |
| Support contract | Optional, Platform Core | Bundled in subscription |
| Old version coverage | Extended, including Java 6 and 7 | Per Oracle roadmap |
| Scales with headcount | No | Yes |
To compare like for like, calculate your Oracle position with the Java pricing guide and the employee metric guide, then request Azul pricing for only the estate you need supported.
Compatibility and migration
Zulu is built from OpenJDK and passes the Java compatibility tests, so for ordinary enterprise applications it is a drop in replacement for Oracle JDK. Migration is generally a matter of changing the runtime your applications and pipelines pull, then retesting. Azul also offers tooling to inventory Java usage and assist the transition, which can shorten the discovery phase of a migration project.
One genuine Azul strength is coverage of very old Java versions. Enterprises stranded on Java 6 or 7 by legacy applications, which Oracle no longer freely supports, can obtain patched, supported builds from Azul, removing both the security risk and the temptation to pay Oracle for legacy support. The general migration method is in the migrating off Oracle Java guide.
Should you choose Azul or a free build?
Choose a free build, whether Zulu Community or Amazon Corretto, if your organisation is comfortable consuming public security updates and operating Java without a support contract, because that path costs nothing and still removes the Oracle subscription. Choose Azul Platform Core if you need contracted support, guaranteed response times, indemnification, or coverage for Java versions that the free builds and Oracle no longer maintain.
The decision should follow your risk and governance requirements, not Oracle's pricing, because both options are free of Oracle's metric. Many enterprises run a mix, using free builds for non critical workloads and a paid support contract for the systems where downtime carries real cost. Either way the Oracle employee subscription is eliminated. Our Java advisory service helps model which mix minimises total cost while meeting your support obligations.
What you actually buy with Azul Platform Core
Because Azul sells support as a product, it is worth being precise about what that product contains, since the value is easy to underestimate when comparing against a free build. Platform Core bundles guaranteed response times for production incidents, access to engineers who work on the JDK itself rather than a generic helpdesk, and security patches delivered on a committed schedule. For an organisation whose Java runs systems that cannot tolerate unplanned downtime, that combination is materially different from consuming public updates on a best efforts basis.
Platform Core also extends coverage to Java versions long after the community and Oracle have moved on. Enterprises stranded on Java 6, 7, or 8 by applications that cannot easily be upgraded face a real security exposure as free patches dry up, and Azul's willingness to keep patching those versions is, for some, the entire reason to engage. It converts a stranded, unsupportable runtime into a supported one without forcing a disruptive application rewrite.
The contrast with Oracle is that Azul's fee buys this support specifically, scaled to the estate that needs it, whereas Oracle's subscription buys the right to run Java at all, scaled to the whole workforce. A buyer evaluating Azul is therefore making a support decision on a contained footprint, not a licensing decision on the entire organisation, which is a fundamentally better shaped purchase. The free alternative is covered in the Amazon Corretto guide.
Modelling total cost across the three options
Choosing between a free build, Azul Platform Core, and the Oracle subscription is best done as a total cost of ownership comparison rather than a sticker price one. The free build has no license or support fee but assumes the organisation absorbs the operational cost of self supporting its Java, which for a mature engineering team is often modest. Azul Platform Core adds a predictable, usage scaled fee in exchange for transferring support risk to a vendor. The Oracle subscription adds a workforce scaled fee that is typically the largest of the three for any organisation whose headcount exceeds its Java footprint.
The decisive variable is usually the ratio between workforce size and Java estate size. A large bank with thousands of staff but Java confined to a few hundred cores will find Oracle's headcount based price wildly out of proportion to its actual usage, making either Azul or a free build dramatically cheaper. A small, Java intensive software company with the opposite ratio sees a smaller gap, though the free and Azul options still avoid the headcount coupling entirely.
Modelling this properly means pricing all three against your real numbers, which requires an honest employee count and an accurate Java inventory. Once those are in hand, the comparison is usually stark rather than close, and it almost never favours the Oracle subscription for a high headcount organisation. The full pricing logic is in the Java pricing guide.
Governance, indemnity, and regulated environments
For regulated industries, the decision to leave Oracle Java is often gated less by cost than by governance, and this is where Azul's commercial model earns its place. Financial services, healthcare, and public sector organisations frequently operate policies that forbid running unsupported software in production, which appears at first to rule out the free builds. Azul Platform Core satisfies that policy by providing a contracted support relationship with defined obligations, allowing such organisations to leave Oracle without breaching their own controls.
Indemnification is a related consideration. Some enterprises require their software vendors to stand behind the product against intellectual property claims, and a formal commercial agreement with a vendor like Azul can provide assurances that consuming a free community build does not. Whether that assurance is necessary depends on the organisation's risk appetite and regulatory context, but where it is required, it is a concrete reason to choose the paid option over the free one, while still avoiding Oracle entirely.
The broader point is that governance requirements rarely force a return to Oracle; they at most steer an organisation from a free build to a paid OpenJDK support contract. Either way the Oracle employee metric is left behind. Mapping which workloads genuinely require contracted support, and which can safely run a free build, is a core part of our Java advisory and audit defence work, and it usually reveals that only a subset of the estate needs the paid tier.
Beyond Zulu: where Azul's specialised runtimes fit
Azul's portfolio extends beyond the standard Zulu builds to specialised runtimes aimed at latency sensitive and high throughput workloads, and understanding where they fit helps a buyer scope the decision correctly. Azul's optimised runtime is engineered to reduce the pauses and warm up effects that affect demanding Java applications, which is relevant to a minority of workloads such as trading systems or large low latency services. For these, the value proposition is performance, not licensing, and it competes with tuning effort rather than with Oracle Java.
For the ordinary enterprise question, which is how to leave Oracle Java without losing support, the standard Zulu builds and Azul Platform Core are the relevant options, and the specialised runtimes are a separate consideration to be evaluated only where a workload genuinely needs them. Conflating the two can make Azul look more complex or expensive than the core decision requires, so it is worth keeping the licensing replacement question distinct from any performance optimisation question.
The clean way to scope it is to treat the move off Oracle Java as the primary decision, satisfied by a free build or Platform Core, and to consider a specialised runtime only as a targeted, separately justified choice for the handful of workloads that warrant it. Most organisations need only the former. Modelling which workloads, if any, justify the specialised tier is part of how our Java advisory service keeps the replacement decision focused and the cost proportionate.
The buyer side view
The practical takeaway is that Azul reframes the Java question from permission to support. Oracle charges you for the right to run Java, priced on your whole workforce; Azul charges you, if at all, only for the support of the Java you actually care about, and gives away the rest. For enterprises that cannot run unsupported runtimes for governance reasons, that distinction makes leaving Oracle possible without leaving support behind.
Weigh the free builds first, since they cost nothing and satisfy most workloads, and reserve paid Azul support for the systems that genuinely require it. Compare Azul's usage based pricing against your Oracle workforce cost, and recognise that even the commercial option typically scales far better for a large headcount organisation. Start with the Java licensing pillar, compare the free route in the Corretto guide, and brief stakeholders with the Java licensing white paper.
Azul Zulu vs Oracle Java: frequently asked questions
Is Azul Zulu free?
Azul offers a free Zulu build suitable for production, patched on the OpenJDK cadence, and a commercial product, Azul Platform Core, that adds contracted support. Both avoid the Oracle Java employee subscription.
How is Azul pricing different from Oracle Java?
Azul commercial pricing is based on the Java estate you want supported, by usage, while Oracle prices on your total workforce. For a large organisation with a small Java footprint, Azul can cost far less.
Can Azul support old Java versions Oracle has dropped?
Yes. Azul provides patched, supported builds for very old versions such as Java 6 and 7, which lets enterprises keep legacy applications secure without paying Oracle for legacy support.