By the Keen To Design Development Team – WordPress specialists with 10+ years experience managing PHP updates for Australian businesses
Your WordPress site’s running PHP 7.2 and you just got that dreaded admin notice. WordPress wants PHP 8.0 minimum these days, and honestly, they’re right. PHP 7.2 stopped getting security updates back in November 2020. That’s ancient history in web years.
As of 2024, here’s where PHP versions stand:
- PHP 8.2 and 8.3: Currently supported with active updates (WordPress recommends PHP 8.2+)
- PHP 8.1: Security fixes only until November 2024
- PHP 8.0: End of life since November 2023 – upgrade immediately
- PHP 7.4: Dead since November 2022 – serious security risk
- Anything below 7.4: Running on borrowed time
WordPress officially recommends PHP 8.2 or higher for best performance and security. While WordPress still technically works on PHP 7.4, you’re missing out on massive performance improvements and exposing your site to known vulnerabilities.
But here’s the thing about PHP updates – they’re not like updating a plugin. Get it wrong and your entire site goes down. I’ve seen perfectly good websites turn into white screens of death because someone clicked the wrong PHP version in cPanel. The good news? It’s completely fixable when you know what you’re doing.
What Actually Happens When You Update PHP
PHP runs every single line of code on your WordPress site. Your theme, plugins, WordPress core, they all need PHP to function. Think of PHP like the engine in your car. WordPress 5.9 needs at least a V6 engine (PHP 7.4), but it runs best with a V8 (PHP 8.0 or higher).
The problem comes when your plugins and themes were built for older engines. Some plugin from 2018 might completely break on PHP 8.2. Database connections can fail. Memory limits get exceeded. Sessions stop working properly.
Here’s what you need to check before touching anything:
- Your current PHP version (check Tools > Site Health in WordPress admin)
- Plugin compatibility (the Plugin Compatibility Checker plugin does this automatically)
- Theme requirements (check your theme documentation)
- Your hosting provider’s available PHP versions
How to Update PHP Through cPanel
Most Australian hosting providers like VentraIP, Crazy Domains, and Crucial use cPanel. The process is nearly identical across all of them, though the exact menu names might vary slightly.
Log into your cPanel account and look for “Select PHP Version” or “MultiPHP Manager”. On older cPanel installations, it might be under “Software” or “Programming”.
In MultiPHP Manager, you’ll see all your domains listed. Find your WordPress site and look at the current PHP version column. Click the checkbox next to your domain, then use the dropdown menu to select your new PHP version.
Start with PHP 7.4 if you’re currently on anything below 7.2. Don’t jump straight to PHP 8.2 – that’s asking for trouble. PHP 7.4 to 8.0 is usually safe, but 7.2 to 8.2 is a massive leap that breaks older code.
After selecting your version, click “Apply”. The change happens instantly. No restart needed. Your site’s now running the new PHP version.
Video: How to Use cPanel’s PHP Selector to Switch PHP Versions
This video walks through the exact process of updating PHP versions using cPanel’s PHP Selector You’ll see how to navigate to the PHP selector, identify your current version, select a new PHP version, and apply the changes safely. The demonstration uses a live WordPress site on Australian hosting to show real-world results.
The Manual .htaccess Method
Some shared hosting doesn’t give you cPanel access. In that case, you’ll need to edit your .htaccess file directly. Connect via FTP (FileZilla works great) and find the .htaccess file in your WordPress root directory.
Add this line at the very top:
AddHandler application/x-httpd-php74 .php
Change “php74” to whatever version you need – php80 for PHP 8.0, php81 for PHP 8.1, and so on. Save the file and upload it back. Clear your browser cache and check if the site loads.
When Things Go Wrong: Common PHP Update Errors
The White Screen of Death
This is the most common PHP update disaster. Your site shows nothing but a blank white page. No error message, no content, just white.
First step: Don’t panic. Your site’s still there, it just can’t execute the code.
Go back to cPanel immediately and revert to your previous PHP version. The site should come back online within seconds. Now you know there’s an incompatibility issue.
To find the culprit, enable WordPress debug mode. Add these lines to your wp-config.php file:
PHP
define( ‘WP_DEBUG’, true );
define( ‘WP_DEBUG_LOG’, true );
define( ‘WP_DEBUG_DISPLAY’, false );
Try the PHP update again. This time, errors get logged to wp-content/debug.log. Check that file to see exactly what’s breaking.
Critical Error Messages
Sometimes WordPress catches the error and shows its “There has been a critical error on this website” message. This is actually better than a white screen because WordPress is still partially working.
Check your email. WordPress 5.2 and newer sends error details to the admin email address. The email tells you exactly which plugin or theme caused the problem.
Can’t access your email? Use FTP to navigate to wp-content/plugins and rename the plugins folder to plugins-backup. This deactivates all plugins at once. If your site comes back, you’ve confirmed it’s a plugin issue.
Rename the folder back to plugins, then go into it and rename individual plugin folders one by one until you find the problematic one. Yes, it’s tedious with 30 plugins, but it works every time.
Database Connection Errors
PHP 8.0 changed how it handles MySQL connections. Older WordPress installations sometimes can’t connect to the database after updating PHP.
The fix is usually simple. Open wp-config.php and find this line:
PHP
define( ‘DB_HOST’, ‘localhost’ );
Change localhost to 127.0.0.1:
PHP
define( ‘DB_HOST’, ‘127.0.0.1’ );
This forces WordPress to use TCP/IP instead of Unix sockets for database connections. Sounds technical, but it’s just telling WordPress to knock on a different door to reach the database.
Important: If this doesn’t fix the database error, revert the change immediately. Some hosting configurations, particularly those using remote database servers or custom socket paths, can develop new problems with 127.0.0.1. Always test your site thoroughly after this change. If you see slower database queries or new connection errors, switch back to ‘localhost’ and contact your host for the correct database connection settings.
Memory Exhausted Errors
PHP 8 is more memory-efficient than PHP 7, but the update process itself can trigger memory issues. You’ll see errors like “Fatal error: Allowed memory size of 134217728 bytes exhausted”.
Add this line to wp-config.php:
PHP
define( ‘WP_MEMORY_LIMIT’, ‘256M’ );
If that doesn’t work, create a php.ini file in your WordPress root directory with:
Ini, TOML
memory_limit = 256M
max_execution_time = 300
Some hosts ignore these settings. Contact support if memory errors persist – they might need to increase limits server-side.
Is Updating PHP Actually Worth the Hassle?
Short answer: Yes, absolutely.
PHP 8.0 is roughly 30% faster than PHP 7.4. That’s not marketing fluff – it’s measurable in real-world WordPress sites. A WooCommerce store processing 100 orders daily could handle 130 orders on the same server just by updating PHP.
Security is the bigger concern though. PHP 7.4 stopped getting updates in November 2022. Every day you run outdated PHP, you’re exposed to known vulnerabilities that hackers actively exploit. The Australian Cyber Security Centre’s latest Annual Cyber Threat Report 2024-2025 shows the severity of the threat – they received over 84,700 cybercrime reports, averaging one report every 6 minutes
Google also factors site speed into search rankings. Faster PHP means better Core Web Vitals scores, which means better SEO. We’ve seen client sites jump 5-10 positions just from PHP updates improving their Largest Contentful Paint times.
When You Should Update PHP
The best time is during low traffic periods. For Australian businesses, that’s usually 2-5 AM on weekdays. Set aside an hour even though the actual update takes seconds. You want time to test and potentially troubleshoot.
Never update PHP right before:
- Major sales or promotions
- Public holidays
- End of financial year
- Critical business periods
Always update PHP after:
- Taking a complete backup
- Testing on a staging site
- Checking all plugin compatibility
- Informing your team about potential downtime
The Step-by-Step Pre-Update Checklist
Before touching that PHP version dropdown, run through this list:
- Backup Everything Use UpdraftPlus, BackWPup, or your host’s backup system. Download the backup locally too. Cloud backups fail sometimes.
- Check Plugin Compatibility Install the PHP Compatibility Checker plugin. Run it against PHP 7.4 first, then your target version. Any errors or warnings need addressing before updating.
- Update Everything First Update WordPress core, all plugins, and your theme. Newer versions usually have better PHP 8 support. That plugin showing errors might already have a fix in its latest version.
- Create a Staging Site Most quality hosts offer one-click staging. SiteGround, WP Engine, and Kinsta all include it. Test the PHP update there first. No staging option? Clone your site to a subdomain using Duplicator.
- Document Your Current Settings Screenshot your current PHP settings in cPanel. Note which extensions are enabled. You might need this information if something breaks.
- Clear All Caches Purge WordPress cache, CDN cache, and browser cache. Old cached files can cause weird issues after PHP updates.
Alternative Update Methods
Through Your Hosting Dashboard
Managed WordPress hosts like WP Engine and Flywheel handle PHP updates differently. They don’t use cPanel but have their own interfaces.
WP Engine users find PHP settings under “Site Settings”. Flywheel puts it in the site’s “Advanced” tab. These hosts usually test PHP versions extensively before making them available, reducing compatibility issues.
Using WP-CLI
Developers prefer command line updates. If you have SSH access, you can check your setup directly. But here’s something most people don’t know – cPanel now includes WordPress Toolkit which gives you WP-CLI access without needing SSH.
In cPanel, find “WordPress Toolkit” (usually under Software). Select your site and click on “WP-CLI”. You get a terminal right in your browser. No SSH keys, no PuTTY, just instant command line access.
Run these commands to check your setup:
Bash
wp cli info
wp plugin list --status=active
wp theme list --status=active
This shows your current setup. The actual PHP switch still happens through cPanel’s PHP selector, but WP-CLI through WordPress Toolkit lets you verify everything’s working after the update:
Bash
wp core verify-checksums
wp plugin verify-checksums --all
For servers with direct SSH access, PHP switching commands vary by host. On GridPane servers:
Bash
gpphp 8.0 yoursite.com
Through WordPress Plugins
Some plugins claim to update PHP for you. Don’t use them. PHP runs at the server level, not within WordPress. These plugins just display your current version or check compatibility. Actual PHP updates must happen at the server or hosting level.
Recovering from a Failed Update
Site completely broken after updating PHP? Here’s your recovery playbook:
- Revert PHP Version Immediately Go back to cPanel and select your previous PHP version. This fixes 90% of issues.
- Access Recovery Mode WordPress 5.2+ has built-in recovery mode. Check your admin email for a recovery link. This lets you access the dashboard even with fatal errors.
- Use FTP for Manual Fixes Can’t access WordPress admin? FTP is your backdoor. Disable plugins by renaming folders. Switch to a default theme by renaming your theme folder.
- Check Error Logs Your host keeps PHP error logs. In cPanel, find “Error Log” under “Metrics”. These logs show exactly what broke and when.
- Contact Host Support Good hosts have seen every PHP update issue imaginable.
- Get Professional Help Still stuck after trying everything? Our team at Keen To Design deals with PHP compatibility issues daily. We’ve recovered sites from every possible PHP update scenario – incompatible plugins, database conflicts, memory issues, you name it.
With over a decade of WordPress development experience in Sydney, our developers have handled PHP migrations for hundreds of Australian businesses, from small local shops to large ecommerce platforms. We understand that Sydney businesses can’t afford extended downtime, especially during trading hours. Contact us if you need immediate help getting your site back online.
The Reality of PHP Updates
Updating PHP isn’t complicated, but it’s unforgiving. One incompatible plugin can take down your entire site. The difference between success and disaster is preparation.
Most WordPress sites can handle PHP 8.0 without issues. PHP 8.1 and 8.2 are trickier with older themes and plugins. Start conservative, test everything, and keep those backups handy.
Your site needs PHP updates to stay secure and fast. Just don’t do it Friday afternoon before a long weekend. That’s a recipe for weekend emergency calls.