Humanizer: A Claude Code Skill That Strips the AI Out of Your Writing

I’m starting a short series on Claude Code skills and plugins that have caught my eye but that I haven’t installed yet. First up: humanizer, a skill by developer blader that’s picked up over 30,000 stars for doing one job well — taking text that reads like it came out of a chatbot and making it sound like a person wrote it.

What it actually does

The skill is built around a list of 33 patterns pulled from Wikipedia’s “Signs of AI writing” guide, the one maintained by WikiProject AI Cleanup for spotting bot-generated edits. Rather than a vague “make this sound more human” instruction, it names specific tells: significance inflation (“marks a pivotal moment”), the rule-of-three habit, em-dash overuse, bolded inline headers, sycophantic chatbot closers, and so on. Each one comes with before/after examples baked into the skill itself.

There’s also a no-fabrication rule, which is the detail I like most. The rewrite pass isn’t allowed to invent facts, names, or dates that weren’t in the original — specificity has to come from the source text or from you, not from the model filling gaps. It finishes with a second “does this still look AI-written” audit pass to catch anything the first rewrite missed.

Voice matching

If you paste in a couple of paragraphs of your own writing first, the skill will pick up on your sentence rhythm and word choices and apply those instead of defaulting to generic “clean” prose. That’s a nice touch for anyone using it on a blog with an established voice.

Installing it

It ships as plain Markdown, so it runs in any harness that supports skill-style instructions. The simplest route is the cross-agent skills CLI:

npx skills add blader/humanizer --global

Claude Code users can also grab it as a plugin directly:

/plugin marketplace add blader/humanizer
/plugin install humanizer@humanizer

Once installed, it’s invoked as /humanizer:humanizer.

Over the next few Sunday afternoons I’ll be working through nine more skills and plugins in the same vein — some for writing, some for security, some for giving Claude a memory of what it’s already done. Next up: Superpowers, obra’s full agentic development methodology.