PHP: Show all errors (E_ALL) safely (2025)

Introduction

If you are trying to debug a PHP issue and need everything visible, this guide shows how to enable and control error display safely in 2025. It covers PHP 8.1–8.4 and the major SAPIs (Apache mod_php, PHP-FPM, and CLI). When I debug locally, I enable E_ALL and display errors; before I deploy, I switch to logging only.

By the way: PHP 8.4 was released on November 21, 2024. See the official news archive on php.net. In PHP 8.4, the E_STRICT level was removed and the E_STRICT constant was deprecated. Referencing it can emit a deprecation notice. See the 8.4 notes in migration 8.4 incompatible changes. Also, the numeric value of E_ALL changed in PHP 8.4 from 32767 to 30719. If you use numeric masks (for example in Apache config), update them. See the summary at php.watch on E_STRICT/8.4.

TL;DR

Development snippet (top of your script):

ini_set('display_errors', '1');
ini_set('display_startup_errors', '1');
error_reporting(E_ALL);

// Alternatively:
error_reporting(-1); // -1 equals E_ALL

php.ini: set display_errors=On, display_startup_errors=On, error_reporting=E_ALL (or -1).
.htaccess (mod_php only): use numerics: php_flag display_errors On, php_flag display_startup_errors On, php_value error_reporting -1.
PHP-FPM: use .user.ini or your FPM pool config; ini_set() cannot override php_admin_* flags.
Production defaults: display_errors=Off, log_errors=On, error_reporting=E_ALL.

Quick snippet (E_ALL)

Place this at the very top of your script to show all errors during development:

ini_set('display_errors', '1');
ini_set('display_startup_errors', '1');
error_reporting(E_ALL);

// Alternatively:
error_reporting(-1); // -1 equals E_ALL

Warning: if a fatal or parse error happens before this runs, it will not display. Set these directives in php.ini, a per-directory .user.ini, your PHP-FPM pool, or use an auto_prepend_file so they run earlier. See the manual’s runtime configuration.

What each setting does

display_errors: Prints errors to output. Use 1 to show, 0 to hide. In CLI you can set the special value stderr so errors go to the error stream. See runtime configuration.
display_startup_errors: Shows errors during PHP startup. Useful for setup issues. Turn off in production.
error_reporting(E_ALL): Reports all errors, warnings, notices, and deprecations. The @ suppression operator still silences specific calls.

Configure by environment

php.ini

Use php.ini for global defaults or to ensure even parse errors are visible while debugging.

Steps:

Find the active php.ini with php --ini (CLI) or by calling phpinfo() in a browser.
Set development values:

display_errors = On
display_startup_errors = On
error_reporting = E_ALL

; or, equivalently:
error_reporting = -1

Restart your SAPI (Apache, Nginx + PHP-FPM, or the PHP built-in server). If errors still do not appear, see Troubleshooting below.

Helpful references: runtime configuration.

Apache .htaccess (mod_php only)

If and only if you run PHP as an Apache module (mod_php), you can enable error display per directory in .htaccess:

# mod_php only, has no effect with PHP-FPM
php_flag display_errors On
php_flag display_startup_errors On
php_value error_reporting -1

Use numeric values in Apache config/.htaccess; constants like E_ALL are not recognized here. See changing PHP configuration.

Important: these directives do nothing on PHP-FPM and may cause a 500 error if used there. See WordPress guidance on display_errors across environments.

.user.ini (PHP-FPM) and FPM pool directives

On PHP-FPM and other FastCGI setups, use a .user.ini (per directory) or pool configuration (per site) instead of .htaccess.

.user.ini example (place in your web root or a specific app directory):

display_errors = 1
display_startup_errors = 1
error_reporting = E_ALL
; or: error_reporting = -1

Notes:

.user.ini is read only by CGI/FastCGI SAPIs. Apache mod_php uses .htaccess instead. See .user.ini files.
Changes may take up to user_ini.cache_ttl seconds (default 300) to apply.

PHP-FPM pool example (e.g., /etc/php/8.3/fpm/pool.d/www.conf):

; Per-pool hard overrides.
php_admin_flag[display_errors] = Off
php_admin_flag[log_errors] = On
php_admin_value[error_log] = /var/log/php_errors.log

; Soft overrides (can be replaced by ini_set).
php_flag[display_errors] = On
php_value[error_reporting] = E_ALL

Settings defined with php_admin_value and php_admin_flag cannot be overridden by ini_set(). The pool config wins. Verify in phpinfo(). See the FPM manual: install.fpm.configuration.

CLI one-off flags

For quick checks on the command line, set directives per run:

php -d display_errors=stderr -d display_startup_errors=1 -d error_reporting=E_ALL script.php

Or with the equivalent numeric setting:

php -d display_errors=stderr -d display_startup_errors=1 -d error_reporting=-1 script.php

Using display_errors=stderr sends errors to the error stream, which is useful for CI and shell pipelines. See runtime configuration.

Verify and diagnose

Check current values (CLI): php -i | grep error_reporting and php -i | grep display_errors.
Syntax check for parse errors: php -l file.php.
Compare SAPIs: run phpinfo() in the web SAPI and php -i in CLI. They often differ (for example, cli vs fpm-fcgi).
.user.ini delay: remember user_ini.cache_ttl can delay changes (default 300 seconds). See runtime configuration.
Numeric masks: on PHP 8.4, E_ALL is 30719 (previously 32767). If you must use numbers (Apache config), use -1 or the correct value for your version.

Troubleshooting: errors still not showing

A fatal or parse error happens before your ini_set line executes. Configure php.ini, a .user.ini, or your FPM pool instead, or use an auto_prepend_file so settings are applied earlier.
You edited the wrong php.ini or the wrong SAPI. Confirm with php --ini (CLI) or phpinfo() in the web SAPI. Sentry’s guide also shows common locations: see How do I get PHP errors to display.
You used Apache .htaccess directives on a PHP-FPM host. Switch to .user.ini or FPM pool configuration. See WordPress’s display_errors.
A framework or custom error handler is intercepting errors. Check your framework toggles (for example, WordPress WP_DEBUG, Laravel APP_DEBUG, Symfony APP_ENV=dev).
The @ operator is suppressing output for specific calls. Search your codebase for @ to find silenced calls.
FPM pool uses php_admin_flag/php_admin_value to lock settings. ini_set cannot override these. See install.fpm.configuration.
The error log path is wrong or not writable. Verify log_errors=On and a valid error_log path, then tail the file.

Production: hide display, log everything

In production, disable display, enable logging, and report all errors. I prefer to log E_ALL, including deprecations, so upgrades do not hide future issues.

// Production-safe defaults.
ini_set('display_errors', '0');
ini_set('log_errors', '1');

// Recommended: log everything, including deprecations.
error_reporting(E_ALL);

// If you must temporarily suppress deprecations in logs:
// error_reporting(E_ALL & ~E_DEPRECATED);

Do not use E_STRICT in masks on PHP 8.4+. The level was removed and the constant is deprecated; referencing it can trigger a deprecation notice. See migration 8.4 incompatible changes.

Server-level logging example (php.ini):

log_errors = On
error_log = /var/log/php_errors.log

On FPM, prefer pool-level php_admin_flag[log_errors] = On and set php_admin_value[error_log] to enforce logging.

Consider advanced debugging tools

For deep debugging in development, use Xdebug, or add error monitoring so production errors are captured without exposing them to users. See Sentry’s step-by-step guide on getting PHP errors to display and its PHP SDK docs. Stackify’s overview also covers the php.ini, in-code, and .htaccess paths with the key parse-error caveat: How to display all PHP errors.

FAQs

How do I show PHP errors with .htaccess?

Use this only with Apache mod_php, and use numerics:

php_flag display_errors On
php_flag display_startup_errors On
php_value error_reporting -1

Constants like E_ALL are not recognized in Apache config. See changing PHP configuration.

Why aren’t my PHP errors showing even with display_errors=On?

Common reasons: wrong SAPI (CLI vs web), a parse error before your code runs, .htaccess directives on an FPM host, php_admin_* flags in your FPM pool locking settings, or .user.ini cache delay. Check with phpinfo(), run php -l file.php, and review FPM pool config. See runtime configuration and install.fpm.configuration.

What’s the difference between E_ALL and -1?

For error_reporting, -1 equals E_ALL. Use whichever is clearer. See error handling constants.

How do I send errors to stderr in CLI?

Run scripts with:

php -d display_errors=stderr -d error_reporting=-1 script.php

See runtime configuration.

How do I enable errors on PHP-FPM?

Use a .user.ini or your FPM pool config. Remember that .user.ini changes can be delayed by user_ini.cache_ttl. ini_set() cannot override php_admin_* pool flags. See .user.ini files and install.fpm.configuration.

Is E_STRICT still needed on PHP 8.4?

No. E_STRICT was removed in PHP 8.4 and the constant is deprecated. Referencing it can trigger a deprecation notice. See migration 8.4 incompatible changes. Also note: E_ALL’s numeric value is 30719 on PHP 8.4 (previously 32767).

Conclusion

Use E_ALL and enable display locally to fix issues fast, then deploy with display disabled and comprehensive logging. Choose the right place to configure it: php.ini for global or early errors, .htaccess for Apache mod_php, .user.ini or FPM pool settings for PHP-FPM, and -d flags for one-off CLI runs. With PHP 8.4 now mainstream, drop E_STRICT and prefer logging everything so deprecations are visible during upgrades. For reference materials, see error_reporting(), ini_set(), runtime configuration, and WordPress’s display_errors.

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