What is Log Deprecated Notices plugin?
Log Deprecated Notices is a WordPress developer plugin that captures and logs calls to deprecated WordPress functions, arguments, hooks, and files. WordPress marks functions as deprecated when they are scheduled for removal in a future version. When deprecated functions are called, WordPress generates a notice internally — but by default these notices are not visible unless WP_DEBUG is enabled.
Log Deprecated Notices makes these notices easy to find by logging them to a dedicated view in the admin dashboard, showing which deprecated function was called, where in the code the call came from (file path and line number), and what the replacement function should be.
This plugin is particularly useful when preparing for a WordPress major version update or when auditing a site to identify themes and plugins that use outdated code. It should be used on development or staging environments, not on production sites.
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Get Log Deprecated Notices Expert HelpKey Features
- Logs deprecated WordPress function calls with file path and line number
- Shows what replacement function should be used instead
- Admin dashboard view of all logged notices
- Distinguishes between deprecated functions, arguments, hooks, and files
- Helps prepare sites for WordPress version upgrades
Pros & Cons
Pros
- Surfaces deprecated code issues that would otherwise require WP_DEBUG enabled
- Shows exactly which file and line number contains the outdated call
- Free and simple to use during development audits
Cons
- Development tool only -- should not be left active on production sites
- Does not fix the deprecated calls, only reports them
Free vs Premium
Log Deprecated Notices is completely free with no premium version.
Common Problems & Fixes
Log Deprecated Notices is not showing any notices even though I know my site uses old code.
Log Deprecated Notices relies on WordPress generating deprecation notices internally. WordPress only generates these notices under certain conditions — the deprecation trigger code must actually execute during a page load. Activate the plugin and then browse the site while logged in, visit different page types, and trigger the functionality that uses older code. Then check the notices log in the admin dashboard. Notices only appear when the deprecated code path is actually executed, not just because the code exists in a file.
I see deprecated notices from a plugin I cannot modify. What do I do?
If deprecated notices come from a third-party plugin or theme, the correct action is to report them to the plugin developer with the specific function name and replacement. Check whether a newer version of the plugin already addresses the deprecated calls. If the plugin is abandoned or the developer is unresponsive, consider replacing it with an actively maintained alternative. Do not modify third-party plugin files directly as changes will be overwritten on the next update.
Log Deprecated Notices is slowing down my admin dashboard.
The plugin intercepts all deprecated function calls during every page load, which adds a small overhead. On sites with many deprecated calls, this overhead accumulates. This is another reason to use the plugin only on staging environments during targeted audits rather than leaving it active permanently. Complete your deprecated code audit, note the issues found, then deactivate the plugin.
Customization & Developer Notes
How do I use Log Deprecated Notices to prepare for a WordPress major version update?
Activate the plugin on a staging copy of your site running the new WordPress version. Browse the site thoroughly — visit the homepage, post pages, archive pages, the shop, account pages, and the admin dashboard. Submit forms and trigger key functionality. After browsing, review the deprecated notices log. Any notices that reference functions being removed in the version you are upgrading to need to be addressed before the upgrade. Contact theme and plugin developers for any notices coming from their code.
Can Log Deprecated Notices help identify compatibility issues with PHP version upgrades?
Log Deprecated Notices is specifically for WordPress API deprecations, not PHP language deprecations. For PHP version compatibility issues, enable PHP error logging on your server or use a tool like the PHP Compatibility Checker plugin which scans plugin and theme files for PHP version compatibility. Both types of checks are useful to run before a PHP upgrade, but they require different tools.
Frequently Asked Questions
What is a deprecated WordPress function?
A deprecated function is one that WordPress has marked for future removal. It still works in the current version but will be removed in a future release. WordPress uses the _deprecated_function() internal function to flag these calls and suggest replacement functions. Deprecated functions are documented in the WordPress developer handbook with the version they were deprecated and what replacement to use. Keeping deprecated function calls in your code creates future compatibility risk.
How is Log Deprecated Notices different from Query Monitor for finding code issues?
Query Monitor includes deprecated notice logging as one of its many features alongside database query analysis, hook timing, and request information. Log Deprecated Notices is a single-purpose tool that only logs deprecated calls. If you are already using Query Monitor, you likely do not need Log Deprecated Notices separately — Query Monitor’s Deprecated Calls panel covers the same ground. Log Deprecated Notices is useful if you want a lighter tool for specifically this one task.
Should I be worried if my site has many deprecated notices?
A large number of deprecated notices means your themes or plugins are using outdated WordPress APIs. This is not an immediate problem if the functions are still present in your current WordPress version, but it is a future compatibility risk. Functions marked deprecated in WordPress 6.x may be removed in WordPress 7.x. Prioritise fixing deprecated calls from your own custom code and report them to plugin and theme developers for third-party code. The more deprecated calls present, the more work a major WordPress update may require.
Can I leave Log Deprecated Notices active on a production site?
It is not recommended. The plugin adds processing overhead on every page load to intercept deprecated calls, and the log it builds up can become large over time. More importantly, it surfaces internal implementation details that do not need to be stored persistently on a production site. Use it on staging during development audits, complete your review, then deactivate it.