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November 13, 2025
Symfony PHP requirements can shape when and how you upgrade your critical applications. Understanding the relationship between Symfony versions and the PHP lifecycle will help you plan ahead, avoid rushed migrations, and keep your stack secure — all while benefiting from modern PHP features and Symfony functionalities.
This guide dives into the Symfony release cycle, clarifies the differences between Standard and LTS versions, and explains how PHP’s lifecycle influences Symfony support. I break down version-to-version Symfony PHP requirements and timelines, and share practical upgrade best practices so I can schedule changes deliberately, reduce risk, and stay focused on delivering value.
How the Symfony Release Cycle Works
Symfony follows a predictable release schedule that helps teams plan upgrades and align with PHP version support. This section explores what you need to know about the basics of the Symfony release cycle.
Symfony Versions and Support Timeline
The Symfony release cycle follows semantic versioning, which helps developers understand the impact of each update. Versions are labeled as major.minor.patch (for example, 6.4.2), and each part of the version number signals a different type of change:
- Major versions (example: 6.x to 7.x) may introduce breaking changes and require careful upgrade planning. These are typically released every two years and often align with PHP advancements.
- Minor versions (example: 6.3 to 6.4) add new features while maintaining backward compatibility. They are released every six months and often include performance improvements and developer experience enhancements.
- Patch versions (example: 6.4.1) contain bug fixes and security updates and are safe to apply without modifying application code.
Each version has a clearly defined support timeline, with standard releases and LTS releases following unique but predictable cadences. By standardizing these timelines, your team can plan Symfony upgrades proactively, avoid technical debt, and align Symfony updates with PHP lifecycle changes — but more on that later.
Standard vs. LTS Symfony Releases
Symfony’s release strategy is designed to balance innovation with stability, offering two distinct types of releases: Standard and Long-Term Support (LTS). Understanding the differences between them helps teams make informed decisions about which version best suits their project’s needs.
Use this table as a quick reference on the differences between standard Symfony releases and LTS Symfony releases:
| Standard Symfony Release | LTS Symfony Release | |
|---|---|---|
| Release Frequency | Every 6 months | Every 2 years |
| Bug Fix Support | 8 months | 3 years |
| Security Fix Support | 14 months | 4 years |
| Best For | Latest features and agility | Stability and long-term support |
Standard Symfony Releases
Standard releases occur twice a year, typically in May and November. These versions introduce new features, improvements, and optimizations that keep Symfony aligned with the latest PHP capabilities and web development trends.
Standard Symfony releases receive bug fix support for eight months, security support for 14 months, and are ideal for teams looking to stay current with Symfony’s latest features.
However, due to the fast-paced release cycle, standard Symfony releases are best suited for developers who are comfortable with frequent upgrades. They require a proactive approach to maintenance, as support windows are relatively short, and it can be easy to fall behind…leaving critical apps vulnerable to possible exploitation.
LTS Symfony Releases
LTS Symfony versions are released every two years, also in November, and are designed for projects that require long-term stability and reduced maintenance overhead.
LTS Symfony releases usually receive three years of bug fix support, four years of security support, and are best suited for applications where frequent upgrades are impractical. This includes enterprise applications, government platforms, or similar projects
In general, LTS versions are a reliable foundation, allowing teams to focus on other tasks versus constantly managing PHP framework upgrades. The drawback is that teams are not always able to access the newest features and functionalities included with standard releases.
Back to topThe PHP Lifecycle and Symfony
PHP follows a well-defined release cycle:
- Active Support: Each PHP version receives bug fixes for two years after its initial release.
- Security Support: After active support ends, PHP versions receive security fixes for two additional years.
- End of Life (EOL): After four years, a PHP version is no longer maintained.
This lifecycle directly impacts Symfony PHP requirements. Symfony aims to support only actively maintained PHP versions, ensuring developers benefit from the latest language features and security improvements.
However, this means that developers must work to not only keep pace with Symfony releases, but also PHP upgrades. Running Symfony on unsupported PHP versions leads to compatibility issues and security risks, and it also means that your team is not accessing the latest PHP features for improving code clarity, reducing boilerplate, and more.
Back to topOn-Demand Webinar: Managing Mission-Critical Web App Migrations
Join Zend Senior Professional Services Engineer Clark Everetts for a webinar exploring how to manage successful PHP web application migrations, including apps built on Symfony framework.
Symfony PHP Requirements by Version
Each Symfony release sets a minimum PHP version based on available language features and security support. In this section, I break down the Symfony PHP version requirements for currently supported and recent Symfony versions, including information on support timelines to help your team plan effective upgrades.
Symfony 5.4 PHP Requirements
Symfony 5.4 requires PHP 7.2.5 or higher.
Symfony 5.4 is a LTS version that originally released in November 2021. It reached the end of bug fixes in November 2024 and will continue receiving security fixes through February 2029. This is a longer-than-average timeline than the typical Symfony release cadence due to a partnership with Ibexa, a company that develops a Digital Experience Platform (DXP) that heavily relies on Symfony 5.4.
Symfony 6.4 PHP Requirements
Symfony 6.4 requires PHP 8.1 or higher.
Symfony 6.4 is the current Symfony LTS version, and it first released in November 2023. It will continue receiving bug fix support through November 2026, and security fixes through November 2027. At this point, it will become unmaintained and be replaced by Symfony 7.4.
Symfony 7.0, 7.1, and 7.2 PHP Requirements
Symfony 7.0, 7.1, and 7.2 require PHP 8.2 or higher.
These Symfony versions were standard releases, following the typical Symfony lifecycle. They are no longer maintained. If your application uses one of these Symfony versions, we recommend upgrading to Symfony 7.4 or 8.0 (upon release) as soon as possible. Doing so will safeguard your critical applications against newly discovered vulnerabilities, malicious attacks, and performance degradation.
Symfony 7.3 PHP Requirements
Symfony 7.3 requires PHP 8.2 or higher.
Symfony 7.3 is a standard version which released in May 2025. We recommend all teams plan their upgrade now to keep your Symfony PHP apps secure, supported, and performing without interruption.
Symfony 7.4 PHP Requirements
Symfony 7.4 requires PHP 8.2 or higher.
Symfony 7.4 is a LTS version releasing in November 2025. Following the typical LTS lifecycle, it will receive bug fixes through November 2028 and security fixes through November 2029. It will also replace Symfony 6.4 as the supported Symfony LTS version, making it the ideal choice for enterprise applications.
Due to the complexity of these upgrades, I recommend all enterprise teams begin preparing their upgrades now to avoid disruption and minimize downtime.
Symfony 8.0 PHP Requirements
Symfony 8.0 requires PHP 8.4 or higher.
Symfony 8.0 is a standard Symfony version releasing in November 2025. It will remain supported until July 2026, as per the typical Symfony release cadence. As of the writing of this post, it is currently under development.
Back to topBest Practices for Meeting Symfony PHP Requirements During Upgrades
Once you know the PHP requirements for your target Symfony version, you can begin to plan your upgrade. While this list is by no means it exhaustive, these best practices can help you stay secure and supported while upgrading your Symfony-based web applications.
Stay on Top of Dependency Management
Dependencies are a double-edged sword in the world of open source, and they can cause a lot of headaches when it comes to managing versions. On one hand, it’s helpful to not need to reinvent the wheel and to take advantage of a package someone built for the community to use. On the other hand, now you’re dependent on it and need to make sure it stays up to date.
Dependencies, such as a PDF generator library, come with a lot of conveniences. They take care of a lot of manual labor, ensuring you’ve got high quality code for whatever you need to accomplish. Still, they do need to be maintained and kept updated. It’s best to consistently check for updates for all your application dependencies, so they’re up to date when you need to update your Symfony stack. Otherwise, you’re left scrambling when it’s time to upgrade.
In other words, stay on top of PHP dependency management.
Plan for Testing and Staging
During any upgrade, whether it’s one dependency or your entire framework, it’s important to perform user testing in an environment that’s separate from both development and production. You don’t want source code changing in the middle of a test scenario, and you also don’t want to surprise production users with untested code.
Beyond setting up your environments, it’s also important to plan your testing and staging strategies before beginning your upgrade process. There are many strategies out there, including the basic dev, test, and deploy all at once strategy.
A personal favorite of mine is a combination of git workflow, strangler pattern, and canary deployment. There are also many ways to accomplish this strategy, but as an example, let’s imagine you have a high availability setup or something similar. All that matters for this example is that you have more than one production server that serves your users.
In this example, we’ll imagine you have a feature branch in your git workflow that has the next version of Symfony that you’re upgrading to, and it’s a constant work in progress that will eventually be merged into your main branch (git workflow). Let’s say you’ve finished a new batch of endpoints, and you stage those and test them thoroughly. When you’re ready, you release only those endpoints (strangler pattern) to certain servers in your high availability stack, so only a subset of production users will interact with the upgraded source code (canary deployment).
This way, if something goes wrong, only a small portion of your users are affected and can raise alarms like canaries in a coal mine.
Communicate and Collaborate With Your Team
Communication is key! Isn’t that what they always say? It's especially true during an upgrade, even more so when you’re dealing with an upgrade that touches the framework for your source code and the language version. These are crucial pieces of your application, so make sure to stay in communication with your teammates and collaborate in a way that makes the process smooth, efficient, and safe. These types of upgrades are exactly when bugs or security flaws can be introduced, and that’s the last thing anyone wants in their business-critical application.
Know your role, delegate properly, raise your hand, thoroughly review and test pull requests, and make sure everyone is on the same page before, during, and after an upgrade. Plan, execute, and review/retrospect. These are key to a successful upgrade.
Complete Symfony and PHP Upgrades Incrementally
I alluded to this earlier when describing environments: completing upgrades incrementally makes the upgrade simpler and safer overall. Planning and defining steps in an upgrade gives the team a checklist to reference throughout the upgrade, which makes the process more straightforward and provides a way to measure completion. It’s especially helpful to plan in such a way that you’re able to deploy pieces of the upgrade to production as you go.
For example, if possible, you could first upgrade your PHP version to make sure your runtime is patched and secure. Then you could upgrade your dependencies and deploy them. Finally, you could upgrade Symfony and deploy it to production. You could also break it down into further steps, which is recommended.
Use PHP Long Term Support to Extend Your Runway
Upgrades can be daunting. They can be especially daunting if you’ve stagnated and not maintained any of the parts for a long time, like the dependencies, Symfony, or the PHP version. I’ve seen plenty of teams do all three, whether it’s because they’re too busy developing features or their focus has been somewhere else in the business.
If you’re facing an upgrade that seems like it might take months, maybe even a year or more, beyond the EOL date for your PHP version, then PHP LTS could be a perfect fit. This would give you peace of mind that your runtime is patched and secure, so you aren’t panicking while upgrading, which would allow you to focus more on the upgrade itself.
Back to topFinal Thoughts
Staying aligned with Symfony PHP requirements and the broader PHP lifecycle comes down to making intentional choices: pick Standard or LTS based on your risk tolerance, map upgrades to support windows, keep dependencies current, and validate changes in staged environments before production. Incremental upgrades and clear team coordination reduce surprises, shorten recovery time when issues arise, and keep you benefiting from new language features without compromising stability.
Symfony Upgrades Made Easy
Let Zend handle the heavy lifting of your next Symfony upgrade. We offer PHP LTS, code audits, compatibility analysis, and expert guidance on breaking changes and modernization processes.