Oracle JDK vs OpenJDK
- Oracle JDK:
- Licensed commercially; requires a fee for use in production.
- Provides extensive support and updates.
- OpenJDK:
- Open source and free for all uses.
- Community-driven; frequent updates.
- Compatible functionality to Oracle JDK.
Oracle JDK vs OpenJDK
Understanding Oracle JDK and OpenJDK
Oracle JDK is Oracle’s official Java distribution, historically free but now requiring a commercial license for production use. OpenJDK is the open-source implementation of Java, available under a GPL license at no cost.
Since Java 11, Oracle’s JDK and OpenJDK share the same code base, so they are essentially identical in features and performance. The real distinctions lie in licensing and support, rather than technical capability.
Licensing and Cost Implications
Oracle changed its Java licensing in 2019, ending free commercial use of Oracle JDK beyond development or personal purposes. The biggest change came in 2023 with the introduction of the Java SE Universal Subscription, which charges based on the total number of employees.
In this model, if you use Oracle JDK in production at all, you must pay for every employee in your organization (including part-time staff and contractors). This all-encompassing requirement has dramatically increased costs.
For example, a company with 500 employees must pay for 500 licenses even if only 50 employees use Java, turning a once-minor expense into a major budget item.
Oracle’s list price starts at approximately $15 per employee per month for smaller organizations, scaling down to around $6–$8 per employee at very large scales. Under this pricing, a firm with 100 employees pays roughly $18,000 per year, and one with 500 employees about $90,000 per year.
Many organizations have seen their Java costs double, triple, or worse under this model. There are cases where annual Java spend jumped from a few thousand dollars to tens of thousands due to the per-employee mandate.
This new licensing model requires a significant financial commitment for Oracle JDK. It also raises compliance stakes: using Oracle’s JDK without proper licensing violates the terms and could lead to penalties.
Unsurprisingly, many enterprises are now looking to avoid this “Java tax” by evaluating alternatives.
OpenJDK: The Free Alternative
OpenJDK is the primary alternative to avoid Oracle’s fees. It is an open-source Java platform, available for free use. Technically, Oracle JDK and OpenJDK are interchangeable for most applications — your Java code will run the same on either.
The huge advantage of OpenJDK is zero licensing cost, but organizations should consider a few factors:
- Updates and Support: OpenJDK receives regular updates for each Java version (especially Long-Term Support releases) through community efforts. Many vendors also offer their own OpenJDK builds with long-term security patches (for example, Red Hat, Amazon, and Azul maintain updates for Java 8, 11, and 17, among others). If you need professional support, these vendors provide it at a much lower cost than Oracle’s plan, often charging per server or core rather than per employee.
- Compliance: With OpenJDK, there are no license fees or audits to worry about. The open-source license (GPL with Classpath Exception) imposes no cost and minimal obligations. In other words, moving to OpenJDK eliminates the risk of a surprise licensing bill from Oracle.
In summary, OpenJDK provides the same Java without ongoing fees. The trade-off is simply that you rely on the open-source community or a third-party vendor for support instead of Oracle. Given the robust Java ecosystem, most organizations find this an acceptable (often preferable) trade-off.
Cost Comparison: Oracle JDK vs OpenJDK
To illustrate the impact, consider the annual costs for Oracle’s subscription versus OpenJDK in different scenarios:
| Scenario (Employees) | Oracle JDK Subscription (Annual) | OpenJDK (Annual License Cost) |
|---|---|---|
| 100 employees (small org) | ~$18,000 | $0 |
| 500 employees (mid-size org) | ~$90,000 | $0 |
| 5,000 employees (large org) | ~$630,000 | $0 |
| 20,000 employees (very large org) | ~$1,620,000 | $0 |
In all cases, OpenJDK has no license cost. Even if you purchase support for OpenJDK from a vendor, it will typically cost only a small fraction of Oracle’s price. The bottom line: switching to OpenJDK can save most organizations tens or hundreds of thousands of dollars annually.
Risks and Considerations
- Vendor Lock-In: Oracle’s model can lock you into their pricing and terms, whereas OpenJDK gives you freedom to switch providers or stay independent. You won’t be at the mercy of a single vendor’s policy changes.
- Compliance: Using Oracle JDK in production without a subscription violates Oracle’s terms. Non-compliance can lead to hefty penalties. OpenJDK, on the other hand, has no such licensing traps — no audits or fees to worry about. (Oracle also doesn’t allow partial coverage; if any production system uses Oracle JDK, they expect you to pay for all employees.)
- Support: Determine how you will get support and updates. Oracle’s subscription includes 24/7 support and regular security patches. If you drop Oracle, plan to obtain updates from the OpenJDK community or a vendor. Many enterprises either rely on third-party support contracts or use internal expertise to handle Java issues.
- Compatibility: Oracle JDK and OpenJDK are fully compatible, but test critical applications in a staging environment after switching. In practice, most organizations report no issues when migrating; however, it’s prudent to verify this with a pilot test.
- Update Management: Oracle delivers Java updates on a fixed quarterly schedule. With OpenJDK, you must stay up to date with updates yourself (or via a vendor). Establish a process to track and apply Java security patches, or plan to upgrade to newer Java versions periodically, to maintain security without relying on Oracle.
Recommendations
- Audit Java Usage: Identify all servers and applications that use Java, and note which ones rely on the Oracle JDK. This reveals your exposure and helps target areas to address.
- Calculate Oracle Cost: Estimate your annual spend if you use Oracle’s Java for all required users (based on your employee count). This figure helps quantify the potential savings from switching.
- Pilot OpenJDK Migration: Test an OpenJDK build (same Java version) on a sample application. If it runs without issues (as expected), plan a broader migration to replace Oracle JDK with OpenJDK across your environments.
- Secure Support (if needed): If your business needs support, compare third-party Java support options. Often, a support contract for OpenJDK (with a vendor like Red Hat or Azul) focused on your Java servers costs far less than Oracle’s all-employee subscription.
- Negotiate or Exit: If you must remain with Oracle for specific reasons, negotiate the best possible terms (use leverage from other Oracle deals or potential volume discounts). Otherwise, prepare to fully exit Oracle JDK usage and communicate this decision internally so all teams switch to the open-source JDK in the future.
Checklist
- Inventory Java Installations: List all systems running Java and note whether they use Oracle’s JDK or an OpenJDK distribution.
- Assess License Exposure: If Oracle JDK is in use, determine the number of employees who would require licensing and estimate the associated cost. Identify any non-compliant usage that needs to be addressed immediately.
- Perform an OpenJDK Pilot: Replace Oracle JDK with OpenJDK on a test system or application (using the same Java version) and confirm that everything works as expected.
- Plan the Migration: Develop a phased plan to deploy OpenJDK across all environments, including testing and roll-out schedules. Ensure no Oracle JDK remains in production by the end of the process.
- Communicate and Document: Inform all stakeholders (IT operations, security, procurement, compliance) of the switch to OpenJDK. Update internal documentation and asset records to reflect the new standard Java platform and prevent the use of Oracle JDK from creeping back in.
FAQ
Q1: Is OpenJDK free for enterprise use?
Yes. OpenJDK is completely free to use in commercial environments. There are no license fees for using OpenJDK on servers or desktops. Just adhere to its open-source license terms (which do not require you to open-source your code).
Q2: What is the difference between Oracle JDK and OpenJDK?
They run the same Java software. The real differences are in licensing and support. Oracle JDK requires a paid subscription for production use and comes with Oracle’s support services. OpenJDK is free to use, and the open-source community or third-party vendors provide updates. In terms of features and performance, they are virtually the same.
Q3: Do we have to pay Oracle to use Java?
Not if you use an OpenJDK distribution. You only need to pay Oracle if you choose to use Oracle’s own JDK in production. Java itself is still free – you can run Java applications on OpenJDK with no fees. Oracle’s subscription is required only if you use their official JDK binaries (or need Oracle’s extended support for older versions).
Q4: How hard is it to migrate from Oracle JDK to OpenJDK?
It’s usually very straightforward. Oracle JDK and OpenJDK are built from the same source code, so your applications should run without modification. In practice, migration often just involves installing an OpenJDK build of the same Java version and pointing your applications to it. It’s wise to test critical systems after switching, but most organizations do not encounter any issues.
Q5: How do we get updates and support without Oracle?
The Java community and various vendors will ensure that your Java runs safely. OpenJDK LTS releases receive regular security updates from the community (often aligned with Oracle’s patch schedule). You can simply apply those updates when they’re released. If you want a guaranteed support channel, you can obtain a subscription from a vendor (such as Red Hat, Azul, or others) to support their OpenJDK builds. These third-party support plans cost significantly less than Oracle’s and ensure you have access to patches and expert help if needed.
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