Free SMF themes

Insidious — a free theme for SMF 2.1

Q: Which versions of SMF do they support?

SMF 2.1, declared as 2.1 - 2.1.99 in each package, built and tested against SMF 2.1.7. They will not work on SMF 2.0 — the template API changed substantially between the two, and these are builds on 2.1’s architecture rather than patched 2.0 themes.

Q: Will they break when I update SMF?

Much less than most custom themes. Each ships only index.template.php and Settings.template.php; every other template is inherited from SMF’s default theme at runtime. When SMF updates a template we do not ship, your forum picks up the new version automatically instead of silently running last year’s markup.

The original Insidious design, rebuilt on SMF 2.1.7’s own architecture rather than patched across from 2.0. Near-black page gradient, a single red accent taken from the logo wordmark, and a post editor that is dark like the rest of the forum.

Free downloads

Get the theme

Running on a real SMF 2.1.7 forum you can click around before you download anything.

Insidious

Dark, red-accented, and built to survive SMF updates.

#070707
#3b3c40
#1c1c1c
#292929
#222222
#a51219

Version 1.2.0
For 2.1 – 2.1.99
Licence MIT
Price Free

Open the Insidious demo →

Share to unlock the download

Insidious costs nothing and carries no adverts. A share is the only thing we ask for it — pick whichever suits you and the download appears.

Download Insidious 1.2.0

Insidious-1.2.0-smf2.1.zip
Served from demo.traxio.co.uk

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62 design tokens

Every colour in the theme — roughly 110 hard-coded hex values in the stock SMF stylesheet — resolves through a named CSS custom property. Re-skinning means editing tokens, not hunting through nine stylesheets.

A dark editor, properly

SCEditor gets its own dark skin. Most dark SMF themes leave the post editor as a bright white box in the middle of a black page.

Two templates, not fifty

Only index.template.php and Settings.template.php ship. Everything else is inherited from the default theme at runtime, so core updates reach your forum.

Architecture

Why they survive SMF updates

Most custom SMF themes are made by copying the default theme, replacing every colour by hand, and shipping all fifty-odd templates. It works on the day it is released. Then SMF publishes a security update that changes a template, and the forum keeps running the copy from two years ago — because the theme overrides it.

Ours ship two templates: the one that draws the page frame, and the one that draws the theme’s own settings. Everything else is inherited from the default theme at runtime, so an SMF update reaches your forum the way it is meant to. That is also why the packages are small.

The colours are handled the same way round. The stock 2.1.7 stylesheet contains roughly 110 hard-coded hex values; in a tokenised theme every one of them resolves through a named custom property declared in a single block at the top of the main stylesheet. Changing the accent colour is one edit, not a search-and-replace across nine files.

Installation

Installing one takes about a minute

Download and unzip nothing

Keep the archive as it is. SMF’s Package Manager expects the zip, not its contents.

Admin → Package Manager

Go to Download Packages, then Upload a Package, and upload the zip you just downloaded.

Install theme

Click Install Theme next to it. SMF unpacks it into /Themes/ and registers it for you.

Set it as the default

Admin → Configuration → Themes and Layout, choose the theme as your default, and set your logo and slogan under its theme settings.

Specification

Compatibility at a glance

SMF theme compatibility compared
	Insidious
Works with	2.1 – 2.1.99
Built and tested on	SMF 2.1.7
Version	1.2.0
Licence	MIT
Design tokens	62
Templates shipped	`index.template.php`, `Settings.template.php`
Stylesheets	Nine, including responsive, RTL, admin, calendar and a dark SCEditor skin
Inherits the rest	Yes
Responsive	Yes
RTL stylesheet	Yes
Modifies core files	No

Questions

SMF themes: common questions

Which theme is on this page?

Insidious. It is ours — designed and built here, not resold or rebadged — and free.

Which versions of SMF do they support?

SMF 2.1, declared as 2.1 - 2.1.99 in each package, built and tested against SMF 2.1.7. They will not work on SMF 2.0 — the template API changed substantially between the two, and these are builds on 2.1’s architecture rather than patched 2.0 themes.

Is the demo the real thing?

Yes. Every demo link on this page opens the same SMF 2.1.7 forum at demo.traxio.co.uk with that theme applied, using SMF’s own ?theme= switch. You are looking at the theme you would install, running on a real forum, not at a screenshot of one.

Is it really free, and can I use it on a commercial forum?

Yes to both. It is released under the MIT licence, so you can use it commercially, modify it and redistribute your modified version. The one condition it imposes is that you keep the copyright and licence text with the files.

Do I have to host with Traxio to use them?

No. They are ordinary SMF themes and work on any host that runs SMF 2.1. We built them because we host a lot of forums, not to lock anything to us.

Will they break when I update SMF?

Much less than most custom themes. Each ships only index.template.php and Settings.template.php; every other template is inherited from SMF’s default theme at runtime. When SMF updates a template we do not ship, your forum picks up the new version automatically instead of silently running last year’s markup.

How do I change the colours?

In the tokenised themes every colour resolves through a CSS custom property declared in one :root block in css/index.css — edit those and the whole theme follows, including the editor and the admin panel. You should not need to hunt through the stylesheets for hex codes.

Do they modify any SMF core files?

No. They install and uninstall as ordinary themes through the Package Manager, and removing one leaves nothing behind.

Where do I get help with them?

Our community forum. These are given away rather than sold, so there is no support contract attached to them — but the forum is where questions get answered and where we hear about bugs.

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