Keeping your PHP version current is one of the easiest ways to improve WordPress performance, security, and compatibility. Before updating PHP across multiple sites, it’s important to verify that themes, plugins, and custom code function correctly on the new version.
This guide explains how to use MCP to inventory your sites, test PHP version changes safely, identify potential compatibility issues, and roll out updates across your Pressable account.
Before You Begin
Before updating PHP versions:
- Update all plugins and themes to their latest available versions.
- Review any custom plugins, themes, or code snippets for compatibility concerns.
- Identify business-critical functionality that should be tested after the upgrade (eCommerce, forms, memberships, integrations, etc.).
Updating PHP before updating plugins and themes can make troubleshooting more difficult if compatibility issues arise.
Step 1: Connect Pressable MCP
Connect your Pressable MCP integration to your AI assistant.
Once connected, the assistant can securely interact with your Pressable account to:
- Inventory sites
- Check versions
- Upgrade WordPress
- Review logs
- And much more!
Step 2: Inventory Your Sites
Use MCP to gather information about all sites in your account, including:
- Current PHP version
- WordPress version
- Installed plugins and themes
- Sites running custom code or custom plugins
This inventory helps identify which sites may require additional testing before upgrading.
Example MCP Prompt
Review all sites in my Pressable account and provide:
Current PHP version
WordPress version
Plugin inventory
Theme inventory
Any plugins or themes that may have PHP compatibility concerns
Step 3: Identify a Representative Test Site
Choose a site that closely matches the configuration of your production sites.
Good candidates include:
- Sites using the same theme
- Sites using the same plugin stack
- Sites with similar customizations
For agencies managing many sites, testing a representative sample is usually more efficient than testing every site individually before rollout.
Example MCP Prompt
Analyze all sites in my Pressable account and identify the best candidate for PHP compatibility testing. Group sites by plugin stack, theme, and custom code usage, and recommend a representative staging candidate.
Step 4: Create a Staging Environment
Create a staging site from the production site you intend to test.
A staging environment allows you to:
- Test the PHP upgrade safely
- Validate site functionality
- Review logs and errors
- Confirm plugin compatibility
without affecting live visitors.
Example MCP Prompt
Create a staging site for example.com and verify that the staging environment is linked and ready for PHP compatibility testing.
Step 5: Update PHP on Staging
Change the staging site’s PHP version to the target release.
After updating PHP, clear any application-level caches and verify the site loads successfully.
Example MCP Prompts
Show me the current PHP version for all production and staging sites in my Pressable account.
Update the PHP version on the staging site for example.com to the latest available version and confirm the change was applied successfully.
Step 6: Perform Functional Testing
Test critical functionality, including:
Site Frontend
- Homepage loads correctly
- Key landing pages render properly
- Navigation menus function
- Search functionality works
WordPress Admin
- Dashboard loads normally
- Editors open correctly
- Media uploads succeed
- Plugin settings pages function
eCommerce Sites
- Product pages load
- Cart functionality works
- Checkout completes successfully
- Payment gateways function properly
Forms and Integrations
- Contact forms submit successfully
- CRM integrations work
- Email delivery functions correctly
- Third-party APIs remain connected
Example MCP Prompts
Compare the plugin inventory on the staging site against known PHP compatibility requirements and flag any plugins that may require updates before deployment.
Review the staging site after the PHP upgrade and identify any plugin, theme, or Site Health issues that may indicate PHP compatibility problems.
Step 7: Check for Errors
Review:
- PHP error logs
- Plugin health notices
- Site Health warnings
- Browser console errors
Look for warnings related to:
- Deprecated functions
- Fatal errors
- Plugin compatibility issues
- Theme compatibility issues
If errors appear, update affected plugins or themes before proceeding.
Example MCP Prompt
Review available diagnostics for the staging site and summarize any warnings, errors, deprecated function notices, or failed health checks that appeared after the PHP upgrade.
Step 8: Roll Out to Additional Sites
Once testing is successful, update additional sites that use the same plugin and theme stack.
For larger accounts, a phased rollout is recommended:
- Test site
- Small group of production sites
- Remaining sites
This approach limits risk while accelerating deployment.
Example MCP Prompts
Identify all sites in my account currently running older PHP versions and group them by plugin and theme stack so I can prioritize PHP upgrades.
Update all sites currently running PHP X.X to the latest version, excluding staging sites and any sites that contain custom plugins.
Step 9: Verify After Deployment
After updating each site:
- Confirm the frontend loads properly
- Verify WordPress admin access
- Test key site functionality
- Review logs for new errors
Most compatibility issues appear immediately after a PHP version change, making post-upgrade validation an important final step.
Example MCP Prompts
Review all sites upgraded during this rollout, confirm they're running the latest PHP version and identify any sites reporting new errors, failed health checks, or plugin compatibility warnings.
Best Practices
Keep Plugins and Themes Updated
Most PHP compatibility issues originate from outdated plugins or themes rather than WordPress core.
Upgrade Incrementally
When moving between significantly different PHP versions, test carefully and validate functionality before continuing.
Prioritize Business-Critical Sites
Upgrade lower-risk sites first if you manage a large portfolio.
Review Custom Code
Custom plugins, mu-plugins, theme modifications, and code snippets are the most common sources of PHP compatibility issues.
Troubleshooting Common Issues
Fatal Errors After Upgrade
Usually caused by:
- Outdated plugins
- Outdated themes
- Custom code using deprecated PHP functionality
Update or temporarily disable the affected component and retest.
Blank Pages or Admin Errors
Check PHP error logs for fatal errors and identify the plugin, theme, or custom code triggering the issue.
Deprecated Function Warnings
These warnings typically indicate code that should be updated before future PHP releases, even if the site continues functioning normally.
Summary
A successful PHP upgrade process follows this pattern:
- Update WordPress, plugins, and themes first.
- Inventory sites using MCP.
- Test PHP changes on staging.
- Validate critical functionality.
- Review logs and errors.
- Roll out incrementally.
- Verify after deployment.
Using MCP alongside Pressable staging environments allows you to identify compatibility issues early and confidently deploy PHP updates across multiple WordPress sites.