How to minify, merge, bundle of HTML / CSS / JS - Magento Cloud vs. Magento Admin

Magento offers a few ways to control minification, merging, and bundling for HTML, CSS, and JavaScript. The approach differs between Magento Commerce Cloud and a standard install configured via the Magento Admin.

1) Configure HTML/CSS/JS on Magento Commerce Cloud (ECE/B2B)

On Cloud, these settings are committed as configuration rather than toggled only in the Admin.

Step 1 — Export environment configuration

From the root of your Magento ECE project (over SSH):

php vendor/bin/m2-ece-scd-dump

This exports environment config to app/etc/config.php.

Need more details? See Magento Cloud docs on exporting store settings.

Step 2 — Edit app/etc/config.php

Add or adjust the relevant dev keys. Use 1 to enable and 0 to disable.

Note on JS merge: If you enable merge_files for JS, also enable JS bundling or the files won’t merge into a single bundle.

'dev' =>
array (
    'static' =>
    array (
        'sign' => '1',
    ),
    'front_end_development_workflow' =>
    array (
        'type' => 'server_side_compilation',
    ),
    'template' =>
    array (
        'minify_html' => '0',
    ),
    'js' =>
    array (
        'merge_files' => '1',
        'minify_files' => '1',
        'enable_js_bundling' => '1',
        'minify_exclude' => '/tiny_mce/',
        'session_storage_logging' => '0',
        'translate_strategy' => 'dictionary',
    ),
    'css' =>
    array (
        'minify_files' => '1',
        'merge_css_files' => '1',
        'minify_exclude' => '/tiny_mce/',
    ),
),

Step 3 — Commit, push, and redeploy

After committing to your Cloud Git repo, clear caches and redeploy static content:

php bin/magento cache:clean
php bin/magento cache:flush
rm -Rf var/cache/ var/generation/ var/page_cache/ var/view_preprocessed/
php bin/magento setup:static-content:deploy -f

Performance tip: Always test. Bundling can reduce requests, but on HTTP/2 it may increase Start Render and DOM Content Loaded times.

Test here: https://www.webpagetest.org

2) Configure HTML/CSS/JS from Magento Admin (Developer Mode)

These options are visible in Developer mode:

Path: Stores -> Configuration -> Advanced -> Developer -> CSS Settings / JavaScript Settings

After saving, clear caches and redeploy static content:

php bin/magento cache:clean
php bin/magento cache:flush
rm -Rf var/cache/ var/generation/ var/page_cache/ var/view_preprocessed/
php bin/magento setup:static-content:deploy -f

Again, validate with a speed test and watch render timings:

Quick guidance

• Cloud: Set values in app/etc/config.php, commit, and deploy.
• Standard installs: Toggle in Admin (Developer mode), then deploy static content.
• HTTP/2 note: Prefer minification over heavy bundling; bundle only if real-world tests show improvements.

Updated on: 18/09/2025