Joomla 3 to 5 migration: test it on a throwaway copy

There is no direct Joomla 3 to 5 migration. You get there in two hops: migrate Joomla 3.10 to Joomla 4 first, which is the heavy step, then upgrade Joomla 4 to Joomla 5 in place, which is easy. Trying to skip the middle does not work. And the real effort is not the core at all, it is getting your extensions and template ready for the new architecture. This guide explains the two-hop path, why the Joomla 3 to 4 step is the hard one, what to check before you start, and how to rehearse the destination on a throwaway copy. Do that first and a broken extension surprises you on a disposable site rather than mid-migration. Want to see the destination first? You can open a free Joomla test site right now and read the rest after.

Can you migrate Joomla 3 straight to Joomla 5?

No. There is no direct Joomla 3 to 5 route, and the official documentation is clear that the path runs through Joomla 4. The Joomla User Manual’s migration guide states you must be current first: “this guide assumes you are starting on Joomla 3.10.x. If you are on an earlier version make sure you upgrade to Joomla 3.10 first before moving to Joomla 4” (Joomla User Manual, 2026). So the sequence is fixed: get to the latest 3.10, migrate to 4, then upgrade to 5.

Joomla 3.10 exists specifically to make that possible. It was released as a bridge between the Joomla 3 and Joomla 4 life cycles, carrying the migration tooling that earlier 3.x versions did not have. If your site is on 3.8 or 3.9, your first move is not the migration at all, it is a normal minor update up to the newest 3.10.x, and only then do you look at Joomla 4.

Why migrate off Joomla 3 at all?

Because Joomla 3 is end of life and no longer receives security fixes. According to endoflife.date, security support for the Joomla 3.x series ended on 17 August 2023 (endoflife.date, 2026), which means any vulnerability found since then stays unpatched on a Joomla 3 site. Running an end-of-life CMS that faces the public web is the kind of risk that gets sites defaced or used to serve malware.

This is not a niche problem. As of July 2026, W3Techs reports that version 3 is used by 54.3% of all the websites that run Joomla (W3Techs, 2026), ahead of the 20.4% on version 5 and 9.5% on version 4. In other words, most Joomla sites on the web are still on the unsupported version. If yours is one of them, the migration is overdue, and the deadline pressure only grows as Joomla 5 and 6 pull further ahead.

Is the Joomla 3 to 4 step a migration or an upgrade?

Joomla’s own manual calls the 3 to 4 step a “mini-migration,” not a routine update, because the core moved to a new architecture. The core files update through the Joomla Update component in one pass, but, as the manual puts it, third-party extensions “require individual assessment” for Joomla 4 compatibility (Joomla User Manual, 2026). That extension assessment is the real work of the whole migration.

The two later steps are much lighter. Once you are on Joomla 4, moving to Joomla 5 is an in-place upgrade rather than a migration, and it stays that way when you later carry the site from 5 up to 6. There is also a PHP floor to clear on the way: Joomla 4 runs on PHP 7.2.5 and up, but Joomla 5 requires at least PHP 8.1.0 and recommends 8.3 (Joomla technical requirements, 2026), so your host has to be on modern PHP by the time you reach the second hop.

The two hops, side by side

The migration is two distinct jobs with very different weights. The first hop, 3.10 to 4, is where the compatibility work lives; the second hop, 4 to 5, is a standard upgrade. The table lays out what each one asks of you, so you can plan the effort honestly before you begin.

Read that way, the plan is simple to hold in your head: clear the PHP floor, get every extension and the template onto Joomla 4, then let the 4 to 5 upgrade carry you the rest of the way. The whole thing lives or dies on extension compatibility, which is exactly why you want to know your blockers before you touch the live site.

Your pre-migration checklist

Start with Joomla’s built-in Pre-Update Check, which was added to the Joomla Update component in 3.10 for this exact job. It reports the compatibility of your PHP and SQL settings and your extensions with Joomla 4, “as long as extension developers utilised the targetplatform tag” (Joomla User Manual, 2026). An extension marked compatible is a good sign; a missing tag means the developer never declared it, so you treat that one as unknown until you test it.

So the short pre-migration checklist is: update to the latest Joomla 3.10.x, take a full backup you can roll back to, run the Pre-Update Check and read every extension row, and confirm your host can reach PHP 8.1 or newer for the eventual Joomla 5 step. The Pre-Update Check tells you what Joomla thinks; the next step turns those guesses into confirmed answers.

How do you rehearse the migration on a throwaway copy?

You cannot run your real content through a two-hop migration on a clean sandbox. That is what a local or staging clone is for. But you can answer the question that actually blocks migrations: whether your extensions and template exist on Joomla 5 at all. And you can answer it in minutes. Open a clean Joomla 5.4, recreate your site’s moving parts, and see what survives. Here is the flow:

1. Open a clean Joomla 5.4. Spin up the destination version in one click, on a PHP version it supports. A clean, isolated install opens on a real server in seconds, with no XAMPP and no database to create, so you can see exactly what you are migrating toward.
2. Install your must-have extensions' current releases. Add the Joomla 5 versions of the extensions your live site depends on. You are not cloning content, you are checking whether the components that make your site work even have a working Joomla 5 release.
3. Add your template and click through it. Install your template and load the front end and back end. A Joomla 3 template will often need a Joomla 4 or 5 replacement, so this is where you learn whether yours carries over or needs swapping.
4. Write down the blockers, then walk away. Note every extension or template with no Joomla 5 release, because those are the parts you must replace before the real migration. When you are done, close the tab and the sandbox deletes itself after four hours.

It is a real Joomla install, not a locked-down demo, so extensions install and run exactly as they will on your migrated site. You can open a clean Joomla 5.4 to run this destination check, read how an online Joomla sandbox differs from a shared demo, or, because this is the same disposable-copy idea as any update rehearsal, see our guide to testing a Joomla update before going live. If your only worry is skipping a local server, the guide to trying Joomla without XAMPP covers that too.

WordPress users have had instant throwaway sites for this kind of check for years, and the Joomla community has an open feature request for the same idea, a 2024 GitHub discussion asking for “something like wp-playground but for Joomla” (joomla-cms discussion #43744, 2024). JInstant is that missing piece: a disposable Joomla you open in one click to confirm the destination before a migration.

Extensions decide whether the migration succeeds

This is where the whole plan holds or breaks, because a Joomla 3 extension does not automatically run on Joomla 4 or 5. The core carries itself across, but third-party extensions “require individual assessment,” as the Joomla User Manual says (Joomla User Manual, 2026), and an abandoned extension with no Joomla 4 or 5 release is a hard blocker you have to solve before you migrate, not after.

So go through your extensions one by one. For each must-have extension, check whether the developer ships a current Joomla 5 release and when it was last updated, and note anything on the official Vulnerable Extensions List while you are at it. Then confirm rather than assume: install each one on a clean Joomla 5 and use it. In our own destination checks, the most common blocker is not a subtle bug but a flat absence, a Joomla 3-era extension or template with no Joomla 5 build at all, which tells you straight away to line up a replacement rather than wait for an update that is not coming. If a plugin is going to break your site, you want to meet the failure on a throwaway install, where the fix is to find a replacement, not to restore a backup under pressure.

Should you stop at Joomla 5 or keep going to 6?

Migrate to Joomla 5 first, then treat Joomla 6 as a quick follow-on rather than a separate project. Joomla 5’s full support ends on 13 October 2026, with security-only updates running to 12 October 2027, per endoflife.date (endoflife.date, 2026), so Joomla 6 is the longer-lived home. But the last rung is gentle enough to save for later: moving from 5 to 6 is an in-place upgrade you can rehearse in an afternoon, so there is no reason to attempt one enormous 3 to 6 leap.

The sensible order is to get off end-of-life Joomla 3 and onto a supported version, confirm everything works there, and only then upgrade 5 to 6 when you are ready. If you want to weigh the destination versions themselves, our comparison of Joomla 5 vs Joomla 6 covers which one to land on. Either way, the migration off version 3 is the urgent part; the last hop to 6 can wait a week.

Conclusion

A Joomla 3 to 5 migration is really two jobs: a mini-migration from 3.10 to 4, where all the extension and template work lives, and a light in-place upgrade from 4 to 5. There is no shortcut through the middle, and the thing most likely to break the whole plan is an extension with no release on the new version. That is a problem you want to find early and cheaply. Open a clean Joomla 5.4, install your must-have extensions and template, and see what runs, then go into the real migration knowing exactly what to replace. You can spin up a free Joomla test site in one click and let it delete itself when you are done.

Frequently asked questions

Sources

• Joomla User Manual, “Joomla 3 to 4 Planning and Migration Step by Step” (mini-migration, Pre-Update Check, targetplatform) (retrieved July 13, 2026).
• Joomla Documentation, “Joomla 3.x to 4.x Step by Step Migration” (retrieved July 13, 2026).
• endoflife.date, Joomla support and release cycle (Joomla 3 EOL 17 August 2023; Joomla 5 support dates) (retrieved July 13, 2026).
• W3Techs, Usage Statistics and Market Share of Joomla (version distribution) (retrieved July 13, 2026).
• Joomla Programmers Documentation, Technical Requirements (Joomla 5.4) (retrieved July 13, 2026).
• Joomla Programmers Documentation, Technical Requirements (Joomla 4.4) (retrieved July 13, 2026).
• Joomla Vulnerable Extensions List (retrieved July 13, 2026).
• joomla/joomla-cms, “something like wp-playground but for Joomla” discussion #43744 (4 July 2024, retrieved July 13, 2026).