Template Overrides in Joomla 6: The Complete Step-by-Step Guide

What you'll need	Details
Joomla version	Joomla 6.0 or later (steps also apply to Joomla 4/5 with minor menu wording differences)
Access level	Super User or Administrator, able to reach System → Site Templates
Skills	Basic HTML/PHP reading — you don't need to write PHP from scratch, only edit existing markup
Backup	A recent full site backup (files + database) before editing any override
Optional	FTP/file manager access, only if you prefer editing files outside the browser

This guide covers Joomla 6.0 and 6.1, the current stable release line as of this writing. It walks through creating an override for com_content (the component behind articles and categories), explains the folder structure Joomla expects, and covers the specific error — "Default Layout file is not exists! Please goto to Template Manager and create a new layout first" — that trips up a large number of Joomla admins after they start experimenting with layouts.

What Exactly Is a Template Override, and Why Use It?

Every Joomla component and module ships with default layout files — plain PHP files that decide how content is structured before your template's CSS styles it. A template override is simply a copy of one of those files, placed inside your active template's /html/ folder. When Joomla builds a page, it checks your template folder first; if a matching file exists there, Joomla uses it instead of the original.

That one mechanism unlocks a lot of practical changes:

• Add or remove elements from an article page (byline, tags, related items) without touching core files.
• Change a <ul> list into a card grid, or restructure a module's HTML for a new design.
• Insert custom fields or extra markup at a specific point in a layout.
• Keep every change update-safe — a core Joomla update won't overwrite files sitting inside your template.

Step 1: Open the Template Customise Screen

1. Log in to the Joomla administrator panel.
2. Go to System → Site Templates → Templates (in some menu configurations this appears under Content → Site Templates).
3. Click your active template's name — for a default install this is usually Cassiopeia.
4. You'll land on the Templates: Customise screen, with tabs for Editor, Create Overrides, and Overrides.

Step 2: Create Your First Override (com_content Example)

1. On the Customise screen, click the Create Overrides tab.
2. You'll see three columns: Modules, Components, and Plugins (plus a Layouts section for small reusable partials).
3. Under Components, click com_content to expand it.
4. Click the view you want to override — for a single article page, choose article; for the category listing page, choose category.
5. Joomla copies the matching files straight into your template's html/com_content/[view]/ folder and confirms the override was created.

Step 3: Understand the Override File Structure

Once created, the files sit at a predictable path inside your template:

templates/[your_template]/html/com_content/article/default.php
templates/[your_template]/html/com_content/category/blog.php
templates/[your_template]/html/com_content/featured/default.php

The pattern is always the same: html/[component]/[view]/[layout].php. If a folder doesn't exist yet for a specific view, Joomla's Create Overrides tool creates it for you — you never need to build the folder tree by hand.

Step 4: Edit the Override Safely

1. Back on the Customise screen, open the Editor tab.
2. Expand html → com_content → article and click default.php to open it in the built-in code editor.
3. Make small, targeted edits — most real-world overrides only need one or two lines changed, not a full rewrite.
4. Click Save, then open the page on the frontend to confirm the change rendered correctly.

Step 5: Assign an Alternative Layout (and Avoid the Common Trap)

Instead of replacing the default layout everywhere, you can create a second copy with a different filename — for example card.php next to default.php — and assign it only to specific articles or menu items:

1. Create the extra file inside the same override folder (rename a copy of default.php; never use underscores in the filename, and don't leave an .xml file with the same name in that folder).
2. Go to the article, module, or menu item you want to change.
3. Open the Options or Layout tab and select your new layout from the Alternative Layout dropdown.
4. Save and check the frontend.

This is also exactly where the well-known "Default Layout file is not exists!" error usually starts — see the dedicated section below before you delete or rename an override file that's already assigned somewhere.

Step 6: Manage and Audit Overrides Over Time

As a site grows, overrides pile up quietly. Joomla gives you a dedicated view to keep track:

1. On the Customise screen, open the Overrides tab.
2. You'll see every override currently active for this template, with its file path.
3. Click any entry to jump straight to it in the Editor.
4. After a Joomla core update, revisit this list — the core file your override is based on may have changed, and your copy won't automatically pick up new markup or fixes until you merge them by hand.

Joomla 6 Child Templates vs. Overrides: Which Should You Use?

Joomla 6 introduced native child templates, which let you inherit a parent template's structure and assets while changing fonts, colors, or larger structural pieces — without a separate custom CSS file. This raises a natural question: override, or child template?

Situation	Best tool
Change one or two specific views (article layout, one module's markup)	Template override
Change global fonts, colors, or many small style tokens across the whole site	Joomla 6 child template
You're overriding the majority of a template's files already	Child template (or a full custom template)
You need the change to survive a parent template update automatically	Child template

In practice, most sites use both: a child template for site-wide look and feel, plus a handful of targeted overrides for specific component or module views.

Fixing "Default Layout file is not exists!" (Top Search Query)

Three common causes, roughly in order of how often they show up:

1. A layout override was renamed or deleted after an article, module, or menu item was already set to use it. Go to the item's Options/Layout tab and switch the Alternative Layout dropdown back to Default, or recreate the missing file with the exact name it expects.
2. A template framework plugin (most commonly reported with Helix Ultimate–based templates) has a pending or misconfigured layout setting tied to a specific menu item or extension response (for example, a payment return URL in an e-commerce extension). Check the framework's own layout/page settings for that menu item, not just Joomla's native Template Manager.
3. A third-party extension update changed or removed a view your site previously overrode. Compare the extension's current view files against your override folder and update the filename or content to match.

Frequently Asked Questions

What is a template override in Joomla?

It's a copy of a core component or module layout file, placed inside your active template's /html/ folder. Joomla loads your copy instead of the original, letting you customize output without editing core files.

Where are Joomla template override files stored?

Inside your active template, at templates/[template_name]/html/[component_or_module]/[view]/[layout].php — for example templates/cassiopeia/html/com_content/article/default.php.

How do I create an override for com_content in Joomla 6?

Go to System → Site Templates → Templates → your template → Create Overrides tab → expand com_content → click the view (article, category, etc.). Joomla copies the files automatically.

What causes the "Default Layout file is not exists!" error?

Usually an alternative layout file that a menu item, article, or extension setting references has been renamed, deleted, or was never created. Reset the layout selection to Default or restore the missing file.

Do overrides break after a Joomla update?

They don't disappear, but they can go stale — a core update may change the original file your override was copied from, so your version misses new markup, fields, or fixes until you manually compare and merge the differences.

What's the difference between a template override and a Joomla 6 child template?

An override targets one specific view or module layout. A child template inherits an entire parent template's structure and assets, better suited for site-wide style changes than for editing a single component's output.

Common Mistakes to Avoid

• Editing core files directly instead of creating an override — the next Joomla update wipes the change.
• Deleting or renaming an override file that's still assigned as an Alternative Layout somewhere, which directly triggers the "Default Layout file is not exists!" error.
• Adding underscores or an XML file with the same name in an alternative layout folder — Joomla's naming rules for alternative layouts are strict about this.
• Forgetting to clear the cache after saving a change, then assuming the override doesn't work.
• Never revisiting old overrides after a core update, silently missing new features or security fixes that landed in the original file.
• Overriding an entire component when only one small element needs to change — edit just the specific file/line that needs it, per the checklist above.

What's Next

If most of your customization needs go beyond a couple of view files, it may be time to look at a Joomla 6 child template, or start from a template built with clean, override-friendly code. Browse Joomla templates on MonsterONE — this link may be an affiliate link, and this site may earn a commission if you purchase through it, at no extra cost to you.

✅ Last verified on Joomla 6.1 — August 2026