At Kanhasoft, we’ve seen more than our fair share of legacy PHP apps clinging to life like that old laptop in the corner of the office (you know the one). That’s why we’re saying it plainly: if you’re still running on PHP 5, the time for a PHP 5 to PHP 7 Upgrade isn’t tomorrow—it’s now.
In the world of PHP Application Development, there’s no prize for “most graceful legacy hang‑on” (despite how nostalgic we might feel). So let’s dive into why this matters, how you do it (yes, we’ll even walk through a step‑by‑step PHP upgrade tutorial), and what you stand to gain when you leave PHP 5 behind.
PHP 5 to PHP 7 upgrade — Why the urgency?
First off: yes, PHP 5 end of life has been a thing for a while. But many organisations (and we’re not pointing fingers—okay, maybe a little) still run important applications on it. Maybe it “just works”, maybe the budget says “we’ll fix it later”, or maybe someone’s nostalgic for the days of mysql_query without PDO. Yet the cost of staying put is growing by the day: performance bottlenecks, security risks, compatibility issues, and technical debt mounting like dirty dishes in a dev‑studio kitchen.
At Kanhasoft we believe that PHP App Development deserves better. If your platform is stuck in PHP 5 you’re essentially putting a modern car engine into a horse‑carriage body—and expecting it to fly. It won’t. So let’s talk about why you should upgrade to PHP 7, what hurdles you’ll face, and how we handle them (yes, anecdotes ahead).
Why upgrade to PHP 7? Performance, security & modernity
Let’s cut to the chase: upgrading to PHP 7 isn’t just “nice to have”—it’s a strategic move in the modern digital age. Here are the key benefits of upgrading to PHP 7:
-
Speed improvements: PHP 7 introduces a new Zend Engine which delivers significant performance wins (we’re talking up to twice as fast in some cases). That translates to faster page loads, happier users, and fewer “why is this so slow?” complaints from the business team.
-
Better memory usage: Efficiency matters. With PHP 7 your app uses less memory, which means your infrastructure costs drop (or you can scale more for the same budget).
-
Security & support: PHP 5 no longer receives official security patches. Leaving critical systems on it is a risk—avoidable. Upgrading means you’re back in the realm of supported, maintained, modern stacks.
-
Modern syntax & features: PHP 7 brings scalar type hints, return type declarations, null coalescing operator (
??), spaceship operator (<=>), improved error handling (hello throwable!), and other goodies. That means cleaner, more maintainable code for your teams. -
Compatibility with newer libraries and frameworks: Many PHP libraries now assume PHP 7+ (or even PHP 7.4+). If you stay on PHP 5 you’re locked out of modern ecosystems.
-
Better developer morale: Yes, it’s a subtle benefit, but we’ve seen it: developers working on legacy stacks tend to dread features, bug‑fixes, and deployments. Giving them a modern stack boosts motivation, productivity, and yes, fewer late‑night debug sessions over “Why didn’t that function exist?”
In short: staying on PHP 5 is like running your business in last year’s model—but expecting world‑class performance. Doesn’t make sense, does it?
Upgrade legacy PHP applications: what we’ve seen at Kanhasoft
Over the years at Kanhasoft, we’ve migrated dozens of legacy systems—yes, including ones running on PHP 5 (and sometimes even earlier). One memorable case: a client whose inventory management system was still using PHP 5.3, pre‑namespaces, mysql_* functions, and spaghetti code that made our engineers weep (okay, not literally—but near it). We told them: “We can improve this—but first we’ll upgrade the engine.” After the PHP 5 to PHP 7 upgrade, the system ran 60% faster, outages dropped, and the team finally felt they could innovate instead of just keep the lights on.
What did we learn?
-
The biggest risk isn’t the upgrade itself—it’s assuming nothing will break. Spoiler: something will. But with proper testing, phasing, fallback plans, we’ve made it smooth.
-
Code audit is vital. You’ve got to find deprecated functions (e.g.,
mysql_query,ereg, etc.), check compatibility, take inventory of extensions. -
Incremental migration often wins. You don’t have to flip the switch in one go—especially for large systems. Start modules, stage upgrades, test.
-
Communication matters. The business side needs to be aware: yes, we’re doing the upgrade, and yes, there may be hiccups—but the payoff is real.
-
The ROI is quicker than you think. Faster app, fewer crashes, less maintenance time. That time saved pays for the upgrade.
Because at the end of the day: we innovate, integrate, inspire (as our motto goes at Kanhasoft) — and upgrading your foundation is the bedrock step.
How to upgrade from PHP 5 to PHP 7 (step‑by‑step PHP upgrade tutorial)
Okay, buckle in—here’s the practical path we follow at Kanhasoft when doing a PHP 5 to PHP 7 upgrade in the realm of PHP App Development. Every project is unique, but the framework remains consistent.
| Step | Description |
|---|---|
| Audit & assessment | Review your current PHP version, extensions, codebase, dependencies, incompatible modules, third‑party libraries. |
| Identify deprecated features | mysql_* functions, old ereg regex, split(), some constructors, etc. Also check for removed or changed behaviours. |
| Setup development environment | Clone your system, upgrade PHP to target version (e.g., 7.4 or 8.0 if ending soon), run tests, fix broken code. |
| Refactor | Replace deprecated functionality, apply modern syntax features where appropriate, update libraries/frameworks. |
| Test thoroughly | Unit tests, integration tests, performance benchmarking, user‑acceptance tests. Remember: what worked in PHP 5 might behave differently in PHP 7. |
| Stage deployment | First deploy to a staging/prod‑mirror environment; monitor logs, errors, memory usage, performance. |
| Go live & monitor | After confidence, deploy to production. Monitor closely for unusual errors, regressions, performance dips. |
| Post‑deployment cleanup | Remove old compatibility layers, deprecated extensions, orphaned code. Update your documentation & DevOps processes. |
Important transitions:
-
We recommend moving to PHP 7.4 (for stability) and then planning PHP 8+.
-
Back up everything before you proceed—yes, we’re serious.
-
Use feature toggles or phased rollout if you have large user bases.
-
Engage your QA and users early—sometimes unexpected deprecated functions live deep in obscure modules.
-
Performance test under realistic conditions—just because the dev version looked fine doesn’t guarantee production scale.
PHP 5 compatibility issues with PHP 7: common pitfalls
No sugar‑coating here: upgrading can surface unexpected issues. Here’s what we regularly encounter in our PHP Application Development work at Kanhasoft:
-
Removed functions / extensions: e.g.,
mysql_*functions removed in PHP 7.0;eregremoved;mcryptdeprecated etc. -
Changes in behaviour: For example, certain array functions, object handling, type coercion might differ.
-
Fatal errors vs warnings: PHP 7 is stricter in some cases—what used to be a warning may now be a fatal error.
-
Namespaces & class autoloading quirks: Older code may rely on manual requires instead of Composer/PSR‑4.
-
Performance regressions: Rare, but possible—especially if your code used weird workarounds for PHP 5 limitations. When you upgrade, some of those workarounds may break or become unnecessary—but you still have to test.
-
Third‑party library compatibility: If you’re using a plugin or library that hasn’t been maintained (and still expects PHP 5), you may need to swap it out.
-
Database drivers / extensions: The
mysqlextension is gone;mysqlior PDO must be used. Also, verify version compatibility of related modules and frameworks. -
Memory/GC changes: Some garbage‑collection behaviour in PHP 7 is different—monitor memory usage after upgrade.
-
Time zone and locale subtleties: Yeah, odd things can happen with old code assuming PHP 5 default behaviours.
By anticipating these, we at Kanhasoft build a migration checklist for each PHP upgrade guide we craft internally. That makes the actual upgrade smoother—and less “oh‑no‑watch‑out‑what‑did‑we‑break” stressful.
Benefits of upgrading to PHP 7: real gains you’ll see
We’ve touched on this already, but let’s put it into tangible business terms (since yes, we still talk to non‑dev stakeholders too). Here’s what clients see when we complete a PHP 5 to PHP 7 upgrade under our PHP Application Development services:
-
Lower server costs (due to better memory & execution efficiency)
-
Faster response times → improved user experience → better conversion rates
-
Fewer outages or bugs caused by outdated engine behaviour
-
Easier hiring of developers (they prefer modern stacks) → long‑term productivity gains
-
Access to newer libraries, frameworks, tools → faster feature delivery
-
Better security posture → lower risk profile (important for compliance, especially in UK/USA/Israel/UAE contexts)
-
Reduced maintenance burden → more time for innovation rather than firefighting
In other words: upgrading is not just a cost—it’s investment. At Kanhasoft we often say: “Don’t just keep the lights on—upgrade the wiring.” Because when you’re building PHP App Development solutions for the modern market, you can’t afford to drag legacy weight behind you.
Step‑by‑step PHP upgrade tutorial (for small/medium apps)
If you have a small to medium sized app (say one codebase, one database, not a huge micro‑services cluster), here’s the condensed path we use at Kanhasoft:
-
Clone the production environment locally or on a staging server (same PHP 5 version if possible).
-
Switch the PHP version on staging to PHP 7.x (we pick 7.4 for max support before PHP 8).
-
Run
composer update(if applicable) and identify incompatible packages. -
Search codebase for deprecated patterns:
mysql_query,split(), old constructors (same name as class), etc. -
Replace with modern equivalents: mysqli / PDO, use namespaces, fix class autoloading.
-
Run unit tests (if you have them); if not, create smoke tests for critical flows (login, data entry, API endpoints).
-
Measure performance: baseline PHP 5 times vs PHP 7 times. Capture memory usage, request time.
-
Fix performance hotspots. Example: maybe a function used by 90 % of requests has changed in PHP 7—tune it.
-
Stage deploy: choose a small percentage of users (feature toggle) if multi‑tenant, monitor error logs.
-
After 24–48 hours of zero major issues, full rollout.
-
Cleanup: remove old compatibility layers, update documentation, set PHP 7 as baseline for future feature work.
-
Celebrate (cup of coffee, maybe — we find devs appreciate this).
PHP upgrade guide: when not to rush — the caveats
Just to keep things real: there are scenarios where you might delay or plan more cautiously. At Kanhasoft we always assess:
-
If the system is mission‑critical and downtime is hugely costly, you must plan very carefully (maintenance window, rollback plan).
-
If you rely heavily on unsupported third‑party code that must itself be upgraded (and vendor support is dead), you may need a rewrite rather than a simple upgrade.
-
If your team lacks test coverage, jumping straight to PHP 7 might introduce hidden bugs. Build test suites first.
-
If the budget or timeline is tight, you might phase the upgrade (e.g., move to PHP 7, then later to PHP 8) rather than both at once.
-
If you run on a hosting environment that doesn’t support PHP 7 (rare nowadays, but possible in some legacy VPS or specialized appliances) you’ll need infrastructure updates first.
So yes—we’re enthusiastic about the upgrade—but also pragmatic. We don’t just say “do it” and walk away; we say “yes, do it—smartly”.
How to upgrade from PHP 5 to PHP 7: a Kanhasoft wrap‑up
Alright—so you’ve heard the reasons, seen the steps, and know the risks. Here’s the take‑away: If you’re still using PHP 5, you’re living in a tech‑era past its prime. For modern PHP Application Development you want fast, secure, maintainable, and scalable. PHP 7 delivers that hire PHP developers.
The path isn’t always trivial—but with the right approach (audit, refactor, test, deploy) it becomes manageable—and the payoff is real. At Kanhasoft we’ve helped clients across the USA, UK, Israel, UAE and beyond modernise their stacks, leave behind legacy drag, and free their teams to build the next big thing instead of just firefighting the old one.
Conclusion : PHP 5 to PHP 7
At Kanhasoft, we’ve always championed progress—not for the sake of chasing trends, but because staying current ensures resilience, scalability, and security. The PHP 5 to PHP 7 upgrade isn’t just another technical checkbox—it’s a fundamental leap forward in how modern web applications perform, scale, and evolve.
Let’s be real: legacy systems can be comforting, like an old hoodie. But eventually, they wear thin and stop protecting you from the elements. Likewise, clinging to PHP 5 may feel safe, but it’s a false sense of security—riddled with vulnerabilities, sluggish performance, and development dead ends.
By upgrading to PHP 7, you open the door to future-proof PHP Application Development. You empower your development team, impress your users, and reassure your stakeholders. Whether you’re in the bustling startup scenes of the USA, the innovation hubs of Israel, the compliance‑driven markets of the UK and Switzerland, or the rapidly scaling ecosystems of the UAE—modernization is no longer optional.
FAQs : PHP 5 to PHP 7
Q. What happens if I don’t upgrade from PHP 5?
A. You’ll continue to face increasing risk: security vulnerabilities (no patches), performance limitations, difficulty finding compatible libraries, higher maintenance costs—and you may struggle to hire developers comfortable with archaic stacks.
Q. Can I upgrade directly from PHP 5 to PHP 8?
A. In some cases yes—but we recommend a staged approach (PHP 7 first) because many compatibility issues have been ironed out in moving to PHP 7. Jumping to PHP 8 may add additional complexity. At Kanhasoft we evaluate case‑by‑case.
Q. How long does a typical PHP 5 to PHP 7 upgrade take?
A. Depends on size and complexity: small apps might be upgraded in a few weeks; larger enterprise systems can take months (including audit, refactor, testing). Budget time for planning and monitoring.
Q. Will my application look or behave differently after upgrading?
A. Functionally, it should behave the same (or better). But you’ll likely see faster response times, less memory usage, fewer errors, and be positioned to deliver new features more easily.
Q. Are there cost savings from upgrading?
A. Yes: lower hosting/infrastructure costs (due to improved efficiency), reduced maintenance overhead, fewer downtime incidents, better developer productivity, and access to modern tools that speed feature delivery.
Q. Do I need to rewrite my entire application when upgrading?
A. Not always. Many migrations are upgrades with refactoring. However, if the codebase is extremely outdated, poorly maintained, or heavily reliant on unsupported third‑party modules, a rewrite might be more cost‑effective.
