Upgrading from Drupal 10 to Drupal 11 requires several important steps to ensure compatibility and stability. Here’s a step-by-step guide to help you upgrade smoothly.

✅ 1. Backup Your Site

Before doing anything:

• Backup your codebase
• Backup your database
• Backup your files/ directory

✅ 2. Check System Requirements

Ensure your environment meets the Drupal 11 requirements:

• PHP 8.2 or 8.3 (Drupal 11 requires PHP 8.2+)
• Composer 2.4+
• MySQL 8.0.17+, MariaDB 10.4+, or PostgreSQL 12+

✅ 3. Update Contributed Modules and Themes

Run:

composer outdated "drupal/*"

Then update everything to the latest Drupal 10-compatible versions:

composer update drupal/core-recommended drupal/core-composer-scaffold drupal/core-project-message drupal/* --with-dependencies

Ensure all modules are Drupal 11-ready. Use:

drush pm:list --status=enabled --type=module --no-core

And consult the module pages or issue queues to confirm Drupal 11 compatibility.

✅ 4. Check for Deprecated Code

Use the Upgrade Status module:

composer require 'drupal/upgrade_status:^4.0'
drush en upgrade_status -y

Then visit /admin/reports/upgrade-status to scan for deprecated APIs used by your site.

Also consider using:

composer require mglaman/phpstan-drupal
vendor/bin/phpstan analyse

✅ 5. Update composer.json for Drupal 11

Edit your composer.json to allow Drupal 11:

"require": {
  "drupal/core-recommended": "^11",
  "drupal/core-composer-scaffold": "^11",
  "drupal/core-project-message": "^11"
}

Or run:

composer require drupal/core-recommended:^11 drupal/core-composer-scaffold:^11 drupal/core-project-message:^11 --update-with-dependencies

✅ 6. Run Database Updates

drush updb -y

✅ 7. Export Configuration

drush cex -y

✅ 8. Clear Cache and Rebuild

drush cr

✅ 9. Test Your Site

• Test all functionality
• Review theme compatibility
• Confirm contributed and custom module behavior

✅ 10. Commit & Deploy

Once tested locally or in staging:

• Commit changes
• Deploy to production carefully

Optional: Use drupal/core-dev for Better Dev Tools

composer require --dev drupal/core-dev:^11

Here’s a Bash script to automate most of the Drupal 10 → 11 upgrade process, assuming you’re using Composer and Drush in a typical Drupal 10 project.

🔧 upgrade-to-drupal11.sh

#!/bin/bash

set -e

echo "=== 🧱 Backing up current site ==="
NOW=$(date +"%Y%m%d_%H%M%S")
tar czf backup_code_$NOW.tar.gz .
drush sql-dump --ordered-dump --gzip --result-file=db_backup_$NOW.sql.gz

echo "=== 🧼 Clearing caches ==="
drush cr

echo "=== 🧪 Updating contrib modules ==="
composer update drupal/* --with-dependencies

echo "=== 🚦 Checking for deprecated code ==="
composer require --dev mglaman/phpstan-drupal
vendor/bin/phpstan analyse > phpstan-output.txt || true
echo "Check 'phpstan-output.txt' for deprecated code issues."

echo "=== ✍️ Updating composer.json to allow Drupal 11 ==="
composer require \
  drupal/core-recommended:^11 \
  drupal/core-composer-scaffold:^11 \
  drupal/core-project-message:^11 \
  --update-with-dependencies

echo "=== 📦 Running database updates ==="
drush updb -y

echo "=== 💾 Exporting config ==="
drush cex -y

echo "=== ♻️ Rebuilding cache ==="
drush cr

echo "=== ✅ Drupal 11 upgrade script completed ==="

💡 How to Use

1. Save as upgrade-to-drupal11.sh

2. Make executable:

   chmod +x upgrade-to-drupal11.sh
   

3. Run it from your Drupal root:

   ./upgrade-to-drupal11.sh
   

🔐 Notes

• This script does not verify module compatibility. You should run drush pm:list or use the Upgrade Status module manually to confirm.
• Your hosting environment must support PHP 8.2+.