Performance Benchmark – Oracle JDK vs OpenJDK
Many people assume Oracle’s Java (Oracle JDK) runs faster than the open-source OpenJDK. It’s a common belief in IT circles. But it’s time to bust this myth.
The reality: Oracle’s JDK doesn’t run any faster than OpenJDK — not anymore. Since Java 11, Oracle’s JDK and OpenJDK share the same codebase.
They both use the same HotSpot engine and the same Java class libraries. In everyday use, their performance is nearly identical.
(Years ago, Oracle’s JDK had some exclusive components that fueled the “faster Java” perception. But those days are over — modern OpenJDK is on par with Oracle in every way.)
Pro Tip: “You’re not buying speed. You’re buying a support contract.”
For a full overview of all alternatives, read our guide Oracle JDK vs OpenJDK – Alternatives to Oracle Java.
The Shared Codebase
Oracle JDK and OpenJDK share a single engine under the hood. Both are built from the OpenJDK project’s source code.
That means the core runtime—the just-in-time (JIT) compiler, garbage collectors, and core APIs—is identical. The two JDKs are like twins: one open-source, one carrying Oracle’s name.
Oracle does include a few proprietary add-ons in its build. These are mostly management and monitoring tools, not features that speed up your applications.
In other words, those extra additions don’t affect the execution speed of your business logic.
OpenJDK is actually the official reference implementation of Java. Even Oracle uses it as the foundation for their commercial release.
Functionally, Oracle JDK isn’t a high-performance “special” edition – it’s basically OpenJDK with a different label and some extra packaging.
Importantly, any performance improvements Oracle makes to Java are contributed back to OpenJDK.
There’s no secret Oracle-only optimizer hidden away – all enhancements funnel into the open-source project.
When Java gets faster, both OpenJDK and Oracle JDK benefit equally.
What About Oracle’s “Extra Features”?
Oracle’s JDK indeed used to bundle some exclusive tools.
For years, features such as Java Flight Recorder (JFR) and Java Mission Control (JMC) were only available in the Oracle build.
These tools help monitor and profile Java applications. Back then, if you wanted advanced out-of-the-box monitoring, Oracle JDK had an edge.
Today, that advantage is gone. Oracle contributed Flight Recorder and other formerly commercial features to OpenJDK. Now those capabilities are open source and available to everyone.
There’s no secret performance sauce locked behind Oracle’s paywall anymore. The playing field is level.
The only differences now lie in vendor support and how updates are delivered – not in runtime performance.
Pro Tip: “Performance isn’t hidden behind a paywall anymore.”
For more answers, read our Frequently Asked Questions – Oracle Java vs OpenJDK.
Real-World Performance Observations
So, how do Oracle JDK and OpenJDK stack up in actual use? For the vast majority of workloads, they deliver identical results.
Run your enterprise application on Oracle’s JDK, then run it on OpenJDK — you’ll get the same throughput and response times. There is no noticeable change.
Any differences only appear in synthetic microbenchmarks or extreme corner cases. Even then, they’re tiny – on the order of 1% or so.
Such a small variance is within normal run-to-run fluctuation. In real-world terms, it isn’t very important for enterprise systems.
For example, here’s a look at some typical runtime metrics comparing Oracle JDK and OpenJDK side by side:
| Test Type | Oracle JDK | OpenJDK | Difference |
|---|---|---|---|
| Startup Time | 2.1s | 2.1s | None |
| Throughput | 100% | 99.8% | Negligible |
| Memory Use | 100% | 101% | +1% overhead |
| GC Efficiency | Equal | Equal | None |
As you can see, the numbers are virtually the same. A few milliseconds here or a few megabytes there won’t make or break your application.
And this isn’t just theory — real-world migrations confirm it. Many organizations have swapped Oracle JDK for OpenJDK in production without users even noticing.
Some have done it across hundreds of servers (or thousands of desktops) with zero performance complaints. The applications run just as smoothly on OpenJDK.
Pro Tip: “If you can measure it only in microseconds, it won’t change your renewal bill.”
Enterprise Stability & Reliability
Performance isn’t the only concern — stability matters just as much. Here too, Oracle JDK and OpenJDK are on equal footing.
Both undergo the same rigorous testing to meet Java standards. In fact, Oracle’s JDK must pass the Technology Compatibility Kit (TCK), just like OpenJDK does.
This certification ensures that any Java implementation behaves consistently. In other words, both Oracle and OpenJDK builds meet the same reliability benchmarks.
In day-to-day production, both runtimes are rock solid. Neither has a magical extra stability ingredient.
Most slowdowns or issues trace back to your architecture or environment (database, network, code design) – not the JDK vendor.
Tuning your garbage collection or optimizing database queries yields far more benefit than switching JDK brands. The runtime itself isn’t the weak link.
Don’t just take our word for it – industry leaders like Amazon, Red Hat, and Microsoft trust OpenJDK in their own products and cloud services.
That should give you confidence that it’s truly enterprise-grade and reliable, even at large scale.
Patch Cadence and Update Speed
Some teams worry that moving away from Oracle will mean slower updates or delayed security patches. In reality, OpenJDK updates roll out on the same schedule as Oracle’s.
Oracle releases Java fixes quarterly, and those fixes are also included in OpenJDK.
Many OpenJDK providers (like Amazon Corretto, Azul, and Red Hat) release patched builds within days of Oracle’s updates — sometimes even the same day.
This means you won’t fall behind on critical patches by choosing OpenJDK. The same security and performance improvements are rolled out across all Java distributions at the same time.
Additionally, several OpenJDK vendors offer long-term support for LTS releases that align with Oracle’s timelines.
You can stay on an older Java version with ongoing updates for years, all without an Oracle contract.
It’s up to your organization’s process to apply patches promptly. You won’t lose any protection or stability by switching away from Oracle’s offering.
Pro Tip: “Patch timing is about process discipline, not your JDK logo.”
When Oracle JDK Might Still Make Sense
Stay on Oracle JDK if:
- You need direct vendor support from Oracle for mission-critical systems.
- Your auditors or industry regulations demand official Oracle certification or documentation.
- You run software that is only certified to work with Oracle’s Java (for example, an Oracle WebLogic server deployment).
These scenarios are the exception rather than the rule.
If these situations do apply, an Oracle JDK subscription might be worth the peace of mind.
But if not, OpenJDK will give you the same performance and functionality without the hefty price tag.
Migration Checklist – Performance Readiness
Switching from Oracle JDK to OpenJDK is straightforward when you plan it out. Use this checklist to ensure a smooth, performance-ready migration:
✅ Inventory Oracle JDK installations across your environments.
✅ Select an OpenJDK distribution (e.g., Azul Zulu, Amazon Corretto, or Red Hat’s build).
✅ Test your key applications on the OpenJDK build for startup time, throughput, and memory use.
✅ Monitor application logs and garbage collection behavior for any anomalies during testing.
✅ Run the OpenJDK in parallel (dual-run or A/B test) for a few weeks to ensure everything remains stable before fully switching over.
Completing these steps will give you confidence that nothing is overlooked. You’ll likely find little to no differences in metrics, reinforcing that the switch is low-risk.
Pro Tip: “You don’t optimize Java by paying more. You optimize by measuring.”
Final Take
Oracle JDK and OpenJDK deliver the same performance. They’re essentially twins in speed and capability. Java is Java – the vendor’s logo doesn’t change how fast your code runs.
The difference comes down to cost and support—not technical merit.
So if you do switch, base it on support and licensing needs, not on performance concerns.
In many cases, enterprises save substantial money by moving to OpenJDK, without sacrificing any performance or stability.
Your decision should hinge on factors such as support agreements, compliance requirements, and risk tolerance—not on unfounded performance fears.
OpenJDK is already the default Java runtime in many environments (for example, most Linux distributions).
A broad community and multiple vendors back it.
You’re not charting unknown territory by choosing it.
Plus, you can always get professional support for OpenJDK from various vendors if your business requires it. You’ll have options without being locked into a single provider.
Pro Tip: “Stop chasing milliseconds. Start chasing savings.”
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