WonderCMS
WonderCMS — small is beautiful
WonderCMS holds a remarkable distinction: it's one of the smallest content management systems in the world, with a core of approximately 5 KB of PHP code. The entire system is essentially a single PHP file plus a JSON data file. It's been in development since 2008, making it one of the longest-running Flat File CMS projects, and its focus has always been radical simplicity.
Key features
WonderCMS packs a surprising amount into its tiny footprint. The system includes inline WYSIWYG editing (click on content and edit it directly on the page), a JSON-based data store, a theme system, a plugin architecture, login security with brute-force protection, automatic backups, and SEO-friendly URLs. The admin interface supports approximately 40 languages. There's a one-click theme and plugin installer. The system even includes custom menus and the ability to create non-menu pages.
Admin panel
WonderCMS takes an unconventional approach to administration: there's no separate admin panel. Instead, when you're logged in, an admin toolbar appears on your live site, and you edit content inline — clicking directly on text, headings, or sections to modify them. It's incredibly intuitive for simple edits but limited for complex content management. Settings are accessible through a simple modal dialog from the toolbar.
Content management
All content is stored in a single JSON file (database.js). Pages are simple — a title, content (HTML), and keywords. Creating a new page is as easy as typing a new page name. The content editor is a basic WYSIWYG that handles text, images, and links. There's no Markdown support, no structured content fields, no media library — just straightforward HTML content on pages.
Pros
Incredibly small footprint (~5 KB core). Easiest possible installation — upload one file. Inline editing is intuitive for simple content. Admin in approximately 40 languages. Automatic backups. Free and open source (MIT license). Minimal server requirements. Long development history (since 2008).
Cons
Very limited feature set — basic pages only. No Markdown support. No hierarchical pages (no parent/child structure). Inline editing is limiting for complex layouts. Single JSON file means no easy partial backups. Not suitable for sites beyond a few pages. Minimal SEO tools. Very basic image handling.
Pricing
Free and open source under the MIT license.
Best for
Single-page or very small sites (1–5 pages). Users who want the absolute simplest possible CMS. Quick landing pages or placeholder sites. Learning about CMS concepts with minimal complexity.