In the world of WordPress development, few tools have had as much quiet influence as the _s theme — short for Underscores. Created by Automattic (the makers of WordPress.com), _s was never meant to be flashy. In fact, that’s the point.
Since its release in 2012, _s has helped thousands of developers start clean, fast, and standards-compliant WordPress themes. While newer tools and frameworks have emerged over the years, the legacy of _s still runs deep.
Let’s look at the story of Underscores: where it came from, how it evolved, and where it stands today in a world of block themes and full-site editing.
What Is _s, Exactly?
Underscores is a starter theme — not a theme you install and activate, but one you clone, customize, and build upon. It provides:
-
No styling (intentionally)
-
Semantic HTML5 markup
-
Clean and minimal PHP templates
-
Basic accessibility support
-
WordPress coding standards baked in
The idea was simple: don’t reinvent the wheel. Start with solid, well-documented code and add your design and features on top.
Why _s Became So Popular
-
Official Backing
Built and maintained by Automattic, _s reflected best practices from the people who write WordPress itself. -
No Bloat
Unlike multipurpose themes, _s didn’t include shortcodes, sliders, or design fluff. Developers had full control. -
Educational Value
Many developers learned how WordPress themes work by dissecting _s. It was readable, organized, and taught by example. -
Community Trust
From freelancers to large agencies, devs trusted _s as a blank slate for high-quality custom themes.
Key Milestones in _s Evolution
-
2012: Public release of _s on GitHub and underscores.me
-
2014: Added Sass support via grunt-based generator
-
2016–2019: Gradual improvements in accessibility, template hierarchy, and markup
-
2020+: Decreased updates, as focus in WordPress shifted to block themes and Full Site Editing
Despite fewer recent updates, many developers still use _s as a base or reference point — particularly in classic theme development.
_s in the Block Era
With the introduction of Full Site Editing (FSE), WordPress theme architecture began changing significantly. The rise of block themes (using theme.json, template parts, and block markup) meant starter themes like _s were no longer enough on their own.
Automattic and the broader WordPress community have since been exploring new block-first starter approaches, like:
-
Blockbase – Automattic’s FSE-compatible base theme
-
Theme experiments – Community-led block-based theme templates
-
Create Block Theme – A plugin for exporting custom block themes
Still, for classic PHP-based theming, _s remains relevant — especially for clients or environments where FSE isn’t practical or desired.
Is _s Still Worth Using?
Yes — in the right context.
If you’re building a traditional WordPress theme from scratch (non-block), _s is still one of the cleanest, most reliable places to start.
However, for future-proof, block-based development, you may want to look toward:
-
Blockbase
-
Twenty Twenty-Three or newer default themes
-
Custom builds using
theme.json
The shift from _s to block themes mirrors the larger evolution of WordPress: from PHP-heavy backends to flexible, visual-first design systems.
Final Thoughts
Underscores may not be the default choice for brand-new WordPress projects in 2025, but its impact is still felt. It taught a generation of developers how to build themes the right way — cleanly, structurally, and with intention.
Whether you still use _s or have moved on to modern block tooling, it’s worth recognizing the role it played in shaping how we write WordPress today.
Sometimes, the most important code is the kind you barely notice — because it just works.