Logging - Knowledge of Laravel

What is logging?

Laravel’s logging system is organized around channels — named configurations that define where and how log messages are written. A single log call can write to multiple channels simultaneously: a rotating daily file, a Slack webhook, or a custom handler. Internally, Laravel uses the Monolog library, giving you access to a wide range of handlers and formatters.

The default channel is stack. A stack channel aggregates multiple channels so one log call reaches all of them.

Configuration

Logging configuration lives in config/logging.php. Set the default channel with the LOG_CHANNEL environment variable:

// config/logging.php
'default' => env('LOG_CHANNEL', 'stack'),

Available channel drivers

Driver	Description
`single`	Writes all log messages to one file
`daily`	Rotates log files daily and removes old ones
`slack`	Sends messages to a Slack Incoming Webhook
`stack`	Aggregates multiple channels into one
`syslog`	Writes to the system syslog
`errorlog`	Writes to PHP’s error log
`monolog`	Uses a Monolog handler directly
`custom`	Calls a factory class to build the channel

Log levels

Laravel supports the eight log levels defined in RFC 5424, from highest to lowest severity:

Level	When to use
`emergency`	System is unusable; immediate action required
`alert`	Action must be taken immediately (e.g., database down)
`critical`	Critical conditions; a core feature has stopped working
`error`	Runtime errors that require attention
`warning`	Unexpected behavior that is not yet an error
`notice`	Normal but significant events
`info`	Informational messages (logins, orders confirmed, etc.)
`debug`	Detailed debug information for development

A channel’s level setting is a minimum threshold. A channel set to error only records error, critical, alert, and emergency messages.

Writing log messages

The Log facade

use Illuminate\Support\Facades\Log;

Log::emergency('System is down.');
Log::alert('Database connection lost.');
Log::critical('Payment service is not responding.');
Log::error('Failed to update user data.');
Log::warning('Deprecated method called.');
Log::notice('Configuration file reloaded.');
Log::info('User logged in.');
Log::debug('Query time: 42ms');

Use context to include structured data alongside the message:

<?php

namespace App\Http\Controllers;

use App\Models\User;
use Illuminate\Support\Facades\Log;
use Illuminate\View\View;

class UserController extends Controller
{
    public function show(string $id): View
    {
        Log::info('Showing user profile.', ['user_id' => $id]);

        return view('user.profile', [
            'user' => User::findOrFail($id),
        ]);
    }
}

The `log` helper

Write a log entry without importing the facade:

log('Message from the helper.');

// With a level and context
log('User created.', 'info', ['user_id' => $user->id]);

Contextual information

Pass an array as the second argument to include related data:

Log::info('Login failed.', [
    'user_id' => $user->id,
    'ip'      => $request->ip(),
    'reason'  => 'Password mismatch',
]);

withContext — add context to a channel

Attach context that will appear on all subsequent log entries for the current channel. Useful for request IDs:

Log::withContext(['request-id' => (string) Str::uuid()]);

// Both entries below include request-id automatically
Log::info('Processing started.');
Log::error('An error occurred.');

shareContext — add context to all channels

withContext affects only the current channel. shareContext applies to all channels:

Log::shareContext(['app-version' => config('app.version')]);

Channel configuration

The stack channel

Write to multiple channels with a single log call:

// config/logging.php
'channels' => [
    'stack' => [
        'driver'   => 'stack',
        'channels' => ['daily', 'slack'],
    ],

    'daily' => [
        'driver' => 'daily',
        'path'   => storage_path('logs/laravel.log'),
        'level'  => env('LOG_LEVEL', 'debug'),
        'days'   => 14,
    ],

    'slack' => [
        'driver'   => 'slack',
        'url'      => env('LOG_SLACK_WEBHOOK_URL'),
        'username' => env('LOG_SLACK_USERNAME', 'Laravel Log'),
        'emoji'    => env('LOG_SLACK_EMOJI', ':boom:'),
        'level'    => 'critical',
    ],
],

With this configuration, all debug-and-above messages go to the daily file, while only critical and higher are sent to Slack.

In production, set the Slack channel level to error or critical. Routing every log message to Slack creates noise and buries the alerts that matter.

The daily channel

Rotate log files by date and delete old ones automatically:

'daily' => [
    'driver' => 'daily',
    'path'   => storage_path('logs/laravel.log'),
    'level'  => env('LOG_LEVEL', 'debug'),
    'days'   => env('LOG_DAILY_DAYS', 14),
],

A short days value means old logs are deleted quickly. Keep enough history to diagnose production incidents.

Slack error notifications

Get your Incoming Webhook URL from Slack and add it to .env:

LOG_SLACK_WEBHOOK_URL=https://hooks.slack.com/services/xxx/yyy/zzz

// config/logging.php
'slack' => [
    'driver'   => 'slack',
    'url'      => env('LOG_SLACK_WEBHOOK_URL'),
    'username' => 'Laravel Error Bot',
    'emoji'    => ':fire:',
    'level'    => 'error',
],

Include slack in the stack channel and set LOG_CHANNEL=stack to receive automatic Slack alerts when errors occur.

Writing to a specific channel

// Write only to the Slack channel
Log::channel('slack')->error('Payment service is not responding.');

// Write to multiple channels at once
Log::stack(['daily', 'slack'])->critical('Database connection failed.');

On-demand channels

Build a channel at runtime with Log::build() — no configuration file entry needed. Useful for temporary output or isolated log files per job:

use Illuminate\Support\Facades\Log;

$channel = Log::build([
    'driver' => 'single',
    'path'   => storage_path('logs/import-' . now()->format('Ymd') . '.log'),
]);

Log::stack([$channel])->info('CSV import started.');

Practical example: attaching a request ID in middleware

Adding a unique request ID to every log entry makes it easy to trace a single request through your logs.

Create the middleware

php artisan make:middleware AssignRequestId

Implement handle()

<?php

namespace App\Http\Middleware;

use Closure;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Log;
use Illuminate\Support\Str;
use Symfony\Component\HttpFoundation\Response;

class AssignRequestId
{
    public function handle(Request $request, Closure $next): Response
    {
        $requestId = (string) Str::uuid();

        Log::withContext(['request-id' => $requestId]);

        $response = $next($request);

        $response->headers->set('X-Request-Id', $requestId);

        return $response;
    }
}

// bootstrap/app.php
->withMiddleware(function (Middleware $middleware) {
    $middleware->append(\App\Http\Middleware\AssignRequestId::class);
})

Every log entry for that request now includes request-id:

[2026-03-01 12:00:00] local.INFO: User logged in. {"request-id":"550e8400-...","user_id":1}
[2026-03-01 12:00:00] local.INFO: Dashboard viewed. {"request-id":"550e8400-..."}

Deprecation warnings

Log PHP and Laravel deprecation warnings to catch them before they become breaking changes:

// config/logging.php
'deprecations' => [
    'channel' => env('LOG_DEPRECATIONS_CHANNEL', 'null'),
    'trace'   => env('LOG_DEPRECATIONS_TRACE', false),
],

LOG_DEPRECATIONS_CHANNEL=daily

Laravel Pail — real-time log tailing

Laravel Pail streams your application’s log output directly in the terminal. Unlike the standard tail command, Pail is designed to work with any log driver, including Laravel Nightwatch, Sentry, or Flare.

Pail requires the PHP PCNTL extension.

Install

composer require --dev laravel/pail

Tail logs

# Stream all logs
php artisan pail

# Verbose output (no truncation)
php artisan pail -v

# Include stack traces
php artisan pail -vv

Filter output

# Filter by keyword
php artisan pail --filter="QueryException"

# Filter by message text
php artisan pail --message="Login"

# Filter by log level
php artisan pail --level=error

# Filter by user
php artisan pail --user=1

Summary

Choosing a log level

Level	Use when
`emergency`	The system is completely unusable
`alert`	A human must act immediately
`critical`	A core feature has stopped working
`error`	An unexpected runtime error occurred
`warning`	Something unexpected that is not yet an error
`notice`	A normal but notable event
`info`	A user action or business event to track
`debug`	Detailed information for debugging (not for production)

Choosing a channel

Development: single or daily to write to a file
Production: stack combining daily (file) and slack (critical alerts)
Isolated processes: Log::build() for a dedicated log file per job or import
Real-time monitoring: php artisan pail in the terminal

Production considerations

debug logs may contain sensitive data. Use LOG_LEVEL=error or higher in production.
Rotate log files regularly with the daily channel and an appropriate days value.
Be mindful of rate limits on external services like Slack — route only critical alerts there.

​What is logging?

​Configuration

​Available channel drivers

​Log levels

​Writing log messages

​The Log facade

​The log helper

​Contextual information

​withContext — add context to a channel

​shareContext — add context to all channels

​Channel configuration

​The stack channel

​The daily channel

​Slack error notifications

​Writing to a specific channel

​On-demand channels

​Practical example: attaching a request ID in middleware

​Deprecation warnings

​Laravel Pail — real-time log tailing

​Install

​Tail logs

​Filter output

​Summary

What is logging?

Configuration

Available channel drivers

Log levels

Writing log messages

The Log facade

The `log` helper

Contextual information

withContext — add context to a channel

shareContext — add context to all channels

Channel configuration

The stack channel

The daily channel

Slack error notifications

Writing to a specific channel

On-demand channels

Practical example: attaching a request ID in middleware

Deprecation warnings

Laravel Pail — real-time log tailing

Install

Tail logs

Filter output

Summary