Admin Debug Log

// Admin Debug Log / Kiri Vadivelu / 2026

// Ensure debug mode enabled at wp-config

// if ( ! defined( 'WP_DEBUG' ) )        define( 'WP_DEBUG', true );

// if ( ! defined( 'WP_DEBUG_DISPLAY' ) ) define( 'WP_DEBUG_DISPLAY', false );

// if ( ! defined( 'WP_DEBUG_LOG' ) )     define( 'WP_DEBUG_LOG', true );

// Or use WP Debugging plugin By Andy Fragen

// Register debug log to admin menu

add_action( 'admin_menu', function () {

    add_menu_page(

        'Debug Log',

        'Debug Log',

        'manage_options',

        'debug-log-viewer',

        'debug_log_viewer_page',

        'dashicons-code-standards',

        80

    );

});

// Check for permission to view log

function debug_log_viewer_page() {

    if ( ! current_user_can( 'manage_options' ) ) {

        wp_die( 'Insufficient permissions.' );

    }

    $log_path = defined( 'WP_DEBUG_LOG' ) && is_string( WP_DEBUG_LOG )

        ? WP_DEBUG_LOG

        : WP_CONTENT_DIR . '/debug.log';

    $search = isset( $_GET['s'] ) ? sanitize_text_field( $_GET['s'] ) : '';

    $level  = isset( $_GET['level'] ) ? sanitize_text_field( $_GET['level'] ) : '';

    $entries = [];

    if ( file_exists( $log_path ) ) {

        $lines = file( $log_path, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES );

        foreach ( $lines as $line ) {

            if ( $search && stripos( $line, $search ) === false ) continue;

            if ( $level && stripos( $line, $level ) === false ) continue;

            $entries[] = $line;

        }

    }

    // Show last 500 by default, most recent first

    $entries = array_slice( array_reverse( $entries ), 0, 500 );

    ?>

    <style>

        .dlv-wrap { font-family: monospace; font-size: 13px; }

        .dlv-controls { margin-bottom: 1em; display: flex; gap: 8px; flex-wrap: wrap; }

        .dlv-controls input[type="search"] { width: 320px; }

        .dlv-log {

            background: #1e1e1e; color: #d4d4d4;

            padding: 16px; border-radius: 6px;

            overflow-x: auto; white-space: pre-wrap;

            word-break: break-all;

        }

        .dlv-line { display: flex; gap: 12px; }

        .dlv-lineno { color: #6a9955; min-width: 48px; text-align: right; user-select: none; }

        .dlv-error   { color: #f48771; }

        .dlv-warning { color: #dcdcaa; }

        .dlv-notice  { color: #9cdcfe; }

        .dlv-fatal   { color: #ff6b6b; font-weight: bold; }

        .dlv-empty   { text-align: center; color: #888; padding: 2em; }

    </style>

    <div class="wrap dlv-wrap">

        <h1>Debug Log Viewer</h1>

        <p>

            <strong>File:</strong> <?php echo esc_html( $log_path ); ?><br>

            <strong>Size:</strong> <?php echo file_exists( $log_path ) ? size_format( filesize( $log_path ) ) : 'N/A'; ?>

        </p>

        <form method="get" class="dlv-controls">

            <input type="hidden" name="page" value="debug-log-viewer">

            <input type="search" name="s" value="<?php echo esc_attr( $search ); ?>" placeholder="Search…">

            <select name="level">

                <option value="">All levels</option>

                <option value="PHP Fatal error" <?php selected( $level, 'PHP Fatal error' ); ?>>Fatal</option>

                <option value="PHP Warning" <?php selected( $level, 'PHP Warning' ); ?>>Warning</option>

                <option value="PHP Notice" <?php selected( $level, 'PHP Notice' ); ?>>Notice</option>

                <option value="Deprecated" <?php selected( $level, 'Deprecated' ); ?>>Deprecated</option>

            </select>

            <button type="submit" class="button">Filter</button>

            <a href="<?php echo esc_url( admin_url( 'admin.php?page=debug-log-viewer' ) ); ?>" class="button button-secondary">Reset</a>

        </form>

        <?php if ( empty( $entries ) ) : ?>

            <div class="dlv-empty">No log entries found. Ensure <code>WP_DEBUG</code> and <code>WP_DEBUG_LOG</code> are set to <code>true</code>.</div>

        <?php else : ?>

            <div class="dlv-log">

                <?php foreach ( $entries as $i => $line ) :

                    $cls = '';

                    if ( stripos( $line, 'fatal' ) !== false )        $cls = 'dlv-fatal';

                    elseif ( stripos( $line, 'warning' ) !== false )   $cls = 'dlv-warning';

                    elseif ( stripos( $line, 'notice' ) !== false )    $cls = 'dlv-notice';

                    elseif ( stripos( $line, 'deprecated' ) !== false ) $cls = 'dlv-notice';

                    else                                               $cls = 'dlv-error';

                    ?>

                    <div class="dlv-line">

                        <span class="dlv-lineno"><?php echo count( $entries ) - $i; ?></span>

                        <span class="<?php echo esc_attr( $cls ); ?>"><?php echo esc_html( $line ); ?></span>

                    </div>

                <?php endforeach; ?>

            </div>

        <?php endif; ?>

    </div>

    <?php

}