Changing Your PHP Version

Traxio offers PHP 7.4 through 8.3, and you can switch between them yourself per domain without contacting anyone. This is useful when an application needs a newer version, or when a legacy site will not run on 8.x.

Changing the version

1. Log in to DirectAdmin.
2. Open Account Manager → Domain Setup and select your domain.
3. Choose the PHP version from the selector and save.
4. The change takes effect immediately — no restart or waiting period.

To confirm which version is actually running, create a file in public_html containing <?php phpinfo();, load it in a browser, then delete it. Leaving a phpinfo file public exposes a detailed map of your server configuration.

Which version should you choose?

PHP 8.3 is the default recommendation. It is significantly faster than 7.4 for most workloads and is actively supported with security patches.

PHP 8.1 or 8.2 are sensible if a plugin or framework has not yet been tested against 8.3.

PHP 7.4 should be treated as a temporary measure only. It reached end of life in November 2022 and receives no security updates. If something forces you onto it, plan the upgrade rather than settling there.

Upgrading without breaking your site

Version jumps occasionally break older code. A safe approach:

1. Take a backup first from DirectAdmin, so you can roll back.
2. Update WordPress core, themes and plugins before changing PHP — most incompatibilities are already fixed upstream.
3. Switch the version, then check your site properly: the homepage, a content page, any forms, and the admin area.
4. If something breaks, switch back immediately and check the error log to identify the culprit.

Adjusting PHP settings

Common limits can be changed from the same area of DirectAdmin without a ticket:

• memory_limit — raise if you hit "allowed memory size exhausted"
• upload_max_filesize and post_max_size — both must be raised to upload larger files; changing only one is the usual mistake
• max_execution_time — for long-running imports

Reading errors

When a page returns a blank screen or a 500, the answer is in the PHP error log, reachable from the file manager. Do not enable display_errors on a live site — error output frequently reveals file paths and database details to visitors.

Stuck on an error message? Post it in the community forum with the full text.

Switching to PHP 8.3 is one of the quickest speed wins available — the speed guide shows where it sits in the ordered list.

How to find out what version your application needs

Before switching, check what the software you run actually supports — the answer is usually published and specific:

• WordPress publishes a requirements page; current releases recommend PHP 8.1 or newer and run well on 8.3. The bigger risk is old plugins, not core.
• Forum software varies: current phpBB, MyBB and SMF releases all support PHP 8.x, while very old installs of any of them may not. Check the version you are actually running, not the latest release.
• Custom or inherited code is the wild card. Code written for PHP 5 or 7.0 frequently relies on functions removed in 8.0. If you did not write it and cannot ask who did, test on 8.1 first — it is the gentlest of the 8.x line for legacy code.

A practical shortcut: switch the version, load the site, and check the error log. PHP tells you precisely which function or syntax it objects to, which is faster than auditing the code by hand.

What the version differences actually mean

The headline changes, briefly, so the numbers mean something:

• PHP 8.0 removed a long list of deprecated functions and introduced the JIT compiler. This is the compatibility cliff — code that runs on 7.4 but not on any 8.x almost always breaks here.
• PHP 8.1 and 8.2 added enums, readonly properties and further deprecations. Well-maintained applications crossed these without drama.
• PHP 8.3 is the current recommendation: actively patched, and measurably faster than 7.4 for typical WordPress workloads. For most sites the upgrade is invisible except in the response times.

Performance-wise, the jump from 7.4 to 8.3 is one of the few free speed upgrades that requires no code changes on a compatible site — which is why the speed guide lists it among the first things to check.

Reading the errors a version switch produces

If something breaks after switching, the error log usually contains one of a small set of messages:

• “Call to undefined function” — the code uses a function removed in the new version (or a PHP extension that is not enabled). Note the function name and search for it with the PHP version number; the replacement is nearly always documented.
• “Deprecated:” warnings — not errors. The code still works but uses something scheduled for removal. Safe to leave short-term; worth updating the plugin or theme responsible.
• “syntax error, unexpected…” — genuinely old code using constructs the parser no longer accepts. This one needs a code fix or an older PHP version while you arrange one.
• A blank white page with nothing in the log — check you are reading the right log, and temporarily set WordPress’s WP_DEBUG_LOG if it is a WordPress site. Never enable on-screen errors on a live site.

Frequently asked questions

Does changing the PHP version affect my database or files?

No. The switch changes which PHP interpreter runs your code — files, databases and email are untouched. That is why switching back is always a safe first response if something breaks.

Can I run different versions on different domains?

The version is set per domain in DirectAdmin, so a legacy site can stay on an older version while a new project runs 8.3.

Do I need to restart anything after switching?

No. The change takes effect immediately for new requests. If the site looks unchanged, hard-refresh your browser before assuming the switch failed — you are usually looking at a cached page.

Why does my site say a different version than DirectAdmin shows?

Almost always caching — either a page cache serving old output, or a phpinfo file you loaded before the change. Clear caches and retest. If a genuine mismatch persists, ask in the community forum with both numbers.