Key facts
- SMF 2.1.7, released March 2026, is the latest SMF 2.1 release
- SMF 2.1.5 raised the minimum PHP version to 7.1 and added PHP 8.4 support
- SMF 1.1 and 2.0 were written for the PHP 5 era
- SMF 2.0 to 2.1 is upgraded with SMF's own upgrade script, which keeps posts and members
- SMF works with MySQL, MariaDB and PostgreSQL
- Managed SMF hosting from dijitul is £1 a day + VAT
SMF 2.1 requirements
Simple Machines Forum is free, lightweight and popular with gaming clans, clubs and support communities. The current 2.1 branch needs:
- PHP 7.1 or newer, with PHP 8.4 supported from SMF 2.1.5
- MySQL, MariaDB or PostgreSQL
- The PHP extensions mysqli, gd, mbstring, json and zlib
- Writable attachments, avatars, cache and Packages folders
SMF 2.1 runs scheduled tasks and background tasks such as notifications through its own system. Visitors trigger them by default. We add a server cron that calls SMF's cron script so they run on a steady schedule.
Old SMF 1.1 and 2.0 boards
SMF 2.0 was the main version for over ten years, so a lot of boards are still on it, and some are older still on 1.1. Both were written for PHP 5 and break in places on PHP 8.
- SMF provides an upgrade script that takes 1.1 and 2.0 boards to 2.1 and keeps posts, members and private messages
- Mods installed with the Package Manager need 2.1 versions; uninstall the old ones before upgrading
- Custom themes for 2.0 won't work on 2.1, so the board moves to the default theme until a new one is set up
Where it is safe, we can keep an older SMF board online on a suitable PHP version while the upgrade is tested on a copy. See old website hosting.
Spam, security and email
- Turn on registration verification with a question and answer, plus reCAPTCHA where available
- Require email activation or admin approval for new members
- Use post moderation for new members' first posts
- Keep SMF updated; point releases often include security fixes
- Send email over SMTP from your own domain, with SPF and DKIM set
Our server firewall filters known bad bots before they reach the registration form.
Performance tips
SMF is quick on modest hardware. On bigger boards, set the caching level in Server Settings to use the file cache or Redis, keep the search index on the fulltext or custom index setting rather than the slow standard search, and prune old logs. Running the newest PHP your SMF version supports makes the biggest single difference.
Moving your SMF forum to dijitul
We copy the database and attachments, run SMF's repair_settings tool to fix paths and URLs for the new server, and test login and posting before switching DNS. Then you get managed hosting with daily backups, free SSL and UK support under Complete Hosting for £1 a day + VAT.
Frequently asked questions
Who can host an SMF forum in the UK?
dijitul, a UK hosting company trading since 2006, hosts Simple Machines Forum boards on managed Plesk hosting for £1 a day + VAT. We move your board, set it up on a supported PHP version with a server cron, and include daily backups, free SSL and UK phone support.
Does SMF work on PHP 8?
SMF 2.1 does. SMF 2.1.5 added PHP 8.4 support and raised the minimum to PHP 7.1, and the latest release is SMF 2.1.7. Older SMF 1.1 and 2.0 boards were built for PHP 5 and have problems on PHP 8, so upgrading to 2.1 is the fix.
How do I upgrade SMF 2.0 to 2.1?
Back up the database and files, uninstall mods that don't have 2.1 versions, upload the SMF 2.1 upgrade package and run upgrade.php. Your posts, members and private messages carry across. Custom 2.0 themes won't work, so plan to set up a 2.1 theme afterwards.
What do I do if my SMF forum shows database errors after moving host?
Usually the paths or database details in Settings.php are wrong for the new server. SMF's repair_settings.php tool fixes these from a browser. Upload it to the forum folder, check the suggested settings, save, then delete the tool. dijitul does this as part of migration.
Is SMF still being developed?
Yes. The Simple Machines team still maintain SMF 2.1, with SMF 2.1.7 released in March 2026, and work on a future 3.0 version continues. It remains a sensible free choice for small and medium communities.
Related
Set it up and forget about it
Managed hosting, Plesk, Cloudflare DNS, daily backups and your domain for £1 a day + VAT. We move your site for you.