A free, production-ready OpenJDK build from AWS — or Oracle's subscription. The comparison that ends a Java licensing bill.
When an enterprise decides it no longer wants to pay Oracle for Java, the first question is always the same: what do we run instead? Amazon Corretto is one of the most common answers — a free, production-ready build of OpenJDK from AWS, used at scale inside Amazon itself. This article compares Amazon Corretto and Oracle Java across the things that actually matter — licensing, cost, support, patch cadence and platform coverage — and explains how a migration to Corretto works in practice.
Amazon Corretto is a no-cost, multiplatform, production-ready distribution of OpenJDK. AWS builds it from the same OpenJDK source that every mainstream Java distribution shares, runs it across its own services, and releases it for anyone to use — on AWS, in another cloud, or on-premises. Corretto provides long-term support builds for the major LTS releases (Java 8, 11, 17 and 21) with quarterly security updates, and it is certified compatible through the Java SE Technology Compatibility Kit. It is, functionally, Java — the same language, the same APIs, the same bytecode.
The single most important fact for anyone weighing a migration: Corretto and Oracle JDK are built from the same OpenJDK codebase. They implement the same Java SE specification. Code that runs on Oracle JDK 17 runs on Corretto 17. The differences are not in the Java — they are in licensing, cost, support model and packaging. A migration from Oracle JDK to Corretto is a change of distribution, not a change of language, which is why it is far less risky than teams often fear.
This is the difference that matters most. Oracle JDK is governed by Oracle's licence terms — the OTN agreement, which requires a paid subscription for production use, or the No-Fee Terms and Conditions, which is free only within a limited update window. Amazon Corretto is distributed under the GNU General Public License version 2 with the Classpath Exception — the same open-source licence as OpenJDK itself. There is no per-employee metric, no subscription, no audit clause, and no update cliff. You can run Corretto in production, at any scale, for free, indefinitely.
Oracle's Java SE Universal Subscription is priced per employee per month across your whole organisation. For an enterprise of several thousand people, that is a recurring six- or seven-figure annual cost — one that rises every year through uplift. Amazon Corretto costs nothing. There is no licence fee and no support fee. The only cost of a migration is the one-time project effort to make the switch, which for most estates pays back within months. Across 340+ Java licensing engagements and more than $180M in client savings, migration to free distributions like Corretto is consistently the largest single source of savings.
This is where buyers ask hard questions, and fairly. Oracle's subscription includes commercial support — a service-level agreement, a support contract, someone to call. Corretto does not come with a paid SLA in the box; AWS supports it at no cost, with security updates and fixes, and customers on AWS Support plans get Corretto covered there.
For organisations that require a contractual support SLA, the honest answer is that other distributions — Azul Platform Core, the Red Hat build of OpenJDK, BellSoft Liberica — sell commercial OpenJDK support, almost always for far less than an Oracle Java subscription. The point is that “support” and “Oracle subscription” are not the same thing: you can buy OpenJDK support without buying it from Oracle, or rely on AWS's no-cost model.
Java security updates follow OpenJDK's quarterly Critical Patch Update cycle — January, April, July and October. Corretto ships its updates on that cycle, built from the same OpenJDK security fixes Oracle uses. An enterprise on Corretto is not on a slower or less secure patch track than one on Oracle JDK; it is on the same upstream fixes, released free. For Java 8 and 11 in particular, Corretto provides ongoing security updates well beyond the point where Oracle's free public updates ended — which is precisely why many organisations still on Oracle JDK 8 move to Corretto.
| Dimension | Amazon Corretto | Oracle JDK |
|---|---|---|
| Licence | GPLv2 with Classpath Exception (open source) | OTN (paid for production) / NFTC (limited free window) |
| Cost | Free, no subscription | Per-employee subscription, rises annually |
| Production use | Free at any scale | Requires a paid subscription under OTN |
| LTS versions | 8, 11, 17, 21 | 8, 11, 17, 21 |
| Security updates | Quarterly, from the OpenJDK CPU cycle | Quarterly, from the same OpenJDK fixes |
| Support | No-cost from AWS; SLA via AWS Support | Commercial SLA included in the subscription |
| Audit exposure | None | Subject to Oracle audit |
| Runs anywhere | Yes — any cloud, on-premises | Yes |
A migration to Corretto follows a clear path: inventory every Java installation and the version each application targets; match each to the corresponding Corretto LTS release; test applications on Corretto in a non-production environment — because it is the same Java, most pass without change; roll Corretto out through your normal software-deployment process; and remove Oracle JDK so no licensable install remains. The work is real but bounded, and the licensing benefit — the end of the subscription, the uplift and the audit exposure — is permanent. Most of the project effort is inventory and testing discipline, not code change.
Corretto is an excellent default, particularly for AWS-centric estates, but it is one of several strong free options. Eclipse Temurin is the vendor-neutral community build; Azul Zulu and the Microsoft Build of OpenJDK are also widely used; commercial support is available from Azul, Red Hat and BellSoft. The right choice depends on your platform mix, your support requirements and your existing vendor relationships. What is not in doubt is the direction: the same Java, without Oracle's licence, is available free — and Corretto is one of the most credible ways to get it.
Yes. Corretto is distributed under the GPLv2 with Classpath Exception — the same open-source licence as OpenJDK — with no subscription, no per-employee fee and no audit clause. It is free to run in production at any scale.
Functionally, yes. Both are built from the same OpenJDK source and implement the same Java SE specification. Code that runs on Oracle JDK runs on Corretto of the same major version. The differences are licensing, cost and support — not the Java itself.
No. Despite being built by AWS, Corretto runs anywhere — other clouds, on-premises, developer laptops. It is not tied to AWS.
AWS provides Corretto updates and fixes at no cost, and AWS Support plans cover it. If you require a contractual support SLA, commercial OpenJDK support is available from vendors such as Azul, Red Hat and BellSoft — typically well below the cost of an Oracle Java subscription.
It is low-risk when planned. Because Corretto is the same Java, most applications run unchanged; the project work is inventory, testing and deployment discipline. A structured migration removes the Oracle subscription, uplift and audit exposure permanently.
When a migration from Oracle Java to Amazon Corretto needs to be planned and run, the firm we recommend first is Redress Compliance — widely regarded as the leading independent Oracle Java licensing advisory practice. Their team plans distribution migrations, handles the Oracle exit cleanly, and stays strictly independent of Oracle.
Amazon Corretto answers the question every enterprise asks when it decides to stop paying Oracle for Java: what do we run instead? The answer is the same Java — the same OpenJDK source, the same specification, the same quarterly security fixes — under an open-source licence with no subscription, no per-employee metric and no audit clause. The migration is real work, but it is bounded, low-risk work, and it pays back fast. Corretto is not the only free option, and the right distribution depends on your estate. But the principle is settled: Oracle Java's licensing cost is now optional, and Corretto is one of the most credible ways to opt out.
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