PHP 8.1 Upgrade Plans: How to Stay Ahead of EOL

PHP 8.1 reaches end of life on December 31, 2025, which means that organizations will need to create a PHP 8.1 upgrade plan to remain secure and compliant. However, upgrading PHP is often easier said than done, and the process can quickly become complex, expensive, and time-consuming.

In this blog post, I walk through the PHP lifecycle and highlight the importance of completing a PHP 8.1 upgrade before end of life occurs. I then provide insight on upgrade paths alongside actionable steps you can use to plan your upgrade from PHP 8.1.

Understanding the PHP Lifecycle

PHP is a mature language that has been around for quite a while, and the PHP release cycle has settled into a standard but rapid pace. While feature releases are yearly, the full lifecycle lasts for four years after general release occurs. This is broken down into two years of active support and another two years of security-only support. The full lifecycle for each version of PHP looks like:

1. General availability release
2. Two years of active support, including both bug fixes and security patches
3. Two years of security-only support, which includes security patches only
4. End of Life (EOL), where community support ceases

Previously, PHP versions only received one year of security-only support, but the cycle was extended in June of 2024. Another change to the lifecycle was extending the support cycle through the end of the calendar year. 

Let's look at PHP 8.1 as an example. 

PHP 8.1 released on November 25, 2021, and it received full community support through 2023. It is currently receiving security-only support that will continue through December 31, 2025. At that point, end of life will occur, and PHP 8.1 will no longer receive any support from the community, leaving it vulnerable to security risks, performance degradation, and other consequences.

Why Complete a PHP 8.1 Upgrade to a Supported Version?

Whether you're managing large-scale enterprise applications or a single web app, using the most current PHP version ensures you're leveraging the best the language has to offer. This includes improved security, better performance, and the latest features.

Stronger Security

The most important and prudent reason for using supported PHP versions is security. As long as your source code and server is running supported versions of PHP, you can rest assured that your PHP runtime has the most up-to-date security patches. 

This is especially important in production systems that are publicly accessible. Without support and active security patches, a vulnerability in production could lead to access for bad actors and a breach of sensitive data, potentially causing erosion of brand reputation, loss of customer sentiment, and millions of dollars in damage.

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Improved Performance

Since the release of PHP 7, the community has made performance one of the pillars of each release. The jump in performance from PHP 5 to PHP 7 was massive, and each version since has delivered a measurable performance increase. Studies have shown that every millisecond of page load time directly translates to customer retention and revenue. Thus, it’s important to stay on the latest stable version of PHP to ensure your application is as performant as possible.

Access to the Latest Features

PHP is known for its flexibility and adoption of modern practices and features. Whether it’s blazing the trail or taking inspiration from other languages, PHP continues to evolve and deliver cutting edge features for developers. 

For instance, the Just in Time (JIT) compiler, delivered with PHP 8, enables PHP to skip compilation and run as a true interpreted language, allowing for a slight increase in performance as well as opening the door for CPU-intensive tasks, like machine learning. 

Another new feature was PHP attributes, also introduced in PHP 8, which allow for actionable metadata for classes, methods, functions, and more. For example, #[SensitiveParamter] will ensure the parameter marked by it remains masked where relevant, such as observability & monitoring systems. The new match expression in PHP 8 allows for inline switch statements. Named arguments allows for self-documenting code.

The list goes on and on! PHP, while mature and ready for enterprise-level development, is modern and forward-thinking. Using the most up-to-date version will allow you to make the most of exciting new features as they are introduced.

PHP 8.1 Upgrade Paths

In our recently published 2025 PHP Landscape Report, we found that PHP teams were more likely to upgrade PHP 8.1 to 8.3 compared to PHP 8.1 to 8.2, at 53.18% vs. 46.82% respectively. This made sense and tracked with expectations for several reasons. PHP 8.3 was the most current version at the time of reporting, and upgrading to it instead of PHP 8.2 offers a longer support runway. We expect to see PHP 8.4 to be a popular destination this year for teams completing PHP 8.1 upgrades.

Considerations for Upgrading PHP 8.1 to 8.2, 8.3, or 8.4

When it comes to completing a PHP 8.1 upgrade, regardless of destination, it's important to look for deprecated features and backward-incompatible changes. With deprecated features scheduled for removal, they won't break anything right now. However, your team should start looking for better practices to replace the functionality.

Backward-incompatible features are more pressing, as they're breaking changes that will impact your application the moment you upgrade PHP versions. In minor version changes, it's rare to be affected by these. However, your team should always assess whether they'll impact you or not, and then plan accordingly.

Additionally, if upgrading PHP 8.1 to 8.3 or 8.4, you may need to upgrade incrementally, beginning with upgrading PHP 8.1 to 8.2, then 8.2 to 8.3, and so on. Always take the time to review the appropriate documentation from the PHP community before beginning any upgrade process:

• Upgrade PHP 8.1 to 8.2
• Upgrade PHP 8.2 to 8.3
• Upgrade PHP 8.3 to 8.4

Ready to Plan Your PHP 8.1 Upgrade?

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How to Plan a PHP 8.1 Upgrade and Prepare for EOL

Upgrading to PHP 8.1 is a crucial step for maintaining the performance, security, and functionality of your application. However, the process requires careful planning and execution to avoid unnecessary pitfalls. Whether you decide to handle the upgrade in-house or partner with external experts, understanding the challenges and options available is key to ensuring a successful transition.

Implement In-House Self-Support Strategies

Many teams may consider implementing their PHP 8.1 upgrade plans themselves, but the success of this decision can vary. If you have an in-house team of experts, it’s a good idea to have them regularly update your PHP version and upgrade your source code to be compatible. Otherwise, due to each version of PHP deprecating syntax and functionality, each new version of PHP will introduce technical debt. Furthermore, if your developers continue to build features with deprecated methods, they’re increasing technical debt by writing code that will need to be rewritten later.

There are variables that may make upgrading to the latest PHP version too expensive, though – perhaps even to the point of needing to consider other options such as long term support (LTS) or outsourcing the upgrade. The size of your team may be a bottleneck. The amount of deprecation may be too daunting. A deprecated feature might be key to a major feature of your application, and your team isn’t aware of alternatives or how to modify the source without disrupting the feature. Your team’s expertise of PHP architecture could be limited and prohibitive. Any of these reasons, along with countless others, could hinder your PHP 8.1 upgrade plans.

Due to issues completing a PHP 8.1 upgrade to supported versions, some companies might consider patching their PHP versions themselves by backporting community patches. While possible, this requires in-depth knowledge and expertise of the PHP language architecture. A patch needs to be thoroughly tested to ensure it won’t impact your application by breaking certain features it might touch. It could cause unforeseen problems with the runtime and language itself. The patch might need to be modified for different versions to fix any issues it might introduce.

Learn more about The Hidden Costs of PHP Upgrades >>

Partner With Experienced PHP Professionals to Plan and Execute Your PHP 8.1 Upgrade

Whether you have an experienced in-house team or not, migrating your PHP footprint to a newer version of PHP could take too long. Without foresight, completing a PHP 8.1 upgrade can extend your time on an unsupported version of PHP, therefore prolonging how long your application is vulnerable without PHP security patches. It can also take up a lot of development time, getting in the way of building valuable features.

A lot of businesses have found value in outsourcing migrations and upgrades, freeing their developers to fully focus on projects that add value and revenue to the business. Some prefer to have the effort assessed and written in a report with a step-by-step blueprint for their developers to follow, saving them a ton of time and guaranteeing efficiency and success. Some prefer to outsource the entire migration from start to finish, so they can have peace of mind by having PHP architects handle it.

Learn more about Planning Your Next PHP Migration >>

Implement Third-Party Long Term Support

As previously mentioned, patching can be difficult and complex, which is why it requires experience and expertise. This is why many people look to third-party companies to provide long-term support for their PHP version. Companies like Zend have provided LTS for decades and have deep experience ensuring safe and secure patches. Zend created the Zend Engine, the stable runtime of PHP, all the way back in PHP 4 and has maintained it ever since. Third-party vendors like Zend can provide peace of mind by guaranteeing a secure and stable PHP runtime environment through back-ported security patches.

Learn more about Zend PHP LTS >>

Final Thoughts

PHP 8.1 EOL is coming up fast, and teams will need to be ready with their upgrade plans before December. Doing so will allow your team to access the latest PHP features available, protect your applications against vulnerabilities, and ensure optimal performance.

While tackling PHP 8.1 upgrades in-house is an option, the process often becomes complicated and eats valuable developer time and resources. Seeking professional support from trusted parties like Zend can go a long way in simplifying the process and mitigating risks. By partnering with our global team of experts, you can keep your PHP applications secure, compliant, and updated.

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Additional Resources

• Report - The 2025 PHP Landscape Report
• Resource Collection - 101 Guide to PHP Security
• On-Demand Webinar - Features (and Deprecations) to Watch in PHP 8.4
• Blog - 2025 PHP Usage and Deployment Trends
• Blog - PHP Upgrades: How to Plan and Execute Your Next Upgrade
• Blog - PHP Migrations: When Is Migrating PHP Versions the Right Choice?