When I let AI write on its own, it shows. “It’s not just a tool, it’s a revolution.” Three adjectives in a row. A punchy little line at the end of every paragraph.
For the Carte Blanche Instagram bio, my agent gave me four versions. I turned them all down, too corporate. That’s the kind of text Humanizer is built to clean up, a free skill I installed in Claude.
What it does
Humanizer rewrites AI text so it sounds like a person wrote it, without changing what it says. It is built on the guide Wikipedia’s volunteers use to spot generated text (Signs of AI writing). It looks for 26 tics, including these.
- The fake contrast. “It’s not X, it’s Y.”
- The punchy closer. “Let that sink in.”
- The line that sounds deep. “At its core, what really matters is…”
- Lists of three by reflex. Three examples, three adjectives, even when two would do.
- Sales talk. “An innovative, game-changing solution.”
It makes nothing up. If a sentence needs a number or a name it doesn’t have, it asks you. When you paste a text, it shows you a first draft, what still sounds artificial, then the final version.
Here’s the example its authors give.
Before I’m thrilled to announce that shared drafts are finally here! 🚀 For months, our own team was drowning in files named final_v7.docx, and we knew there had to be a better way. Now two people can edit the same doc at once, with every change appearing live for both of them. It’s not just a feature; it’s a whole new way to collaborate. Comments stay anchored to the exact sentence they reference, even as the text around them evolves. And the best part? It’s available today on every plan, completely free. Let that sink in.
After Shared drafts are out today. For months our own team passed around files named final_v7.docx, so we built a way for two people to edit the same doc at once, with each person’s changes showing up live for the other. Comments stay pinned to the sentence they’re about, even when the text around them changes. It’s free on every plan.
Why I use it
When a text smells like AI, people stop reading. And they wonder what else you handed off without looking.
The text also gets shorter. In the example, the after says everything the before says with a third fewer words. When you write to a client, that matters.
It doesn’t do everything. The word tics go. The structure stays, like repeating the same lesson at the end of every section, or ending every piece on a note that’s too neat. For that, I still read it over. And its authors say so themselves, AI detectors still flag most of its output. It writes for the person reading.
Installing it
A skill is a file of instructions the AI reads when your request matches it. You install it once, and it uses it every time you ask it to rewrite something. Before you install a skill you found online, open it and read it. This one fits in a single text file, SKILL.md, on its page.
In Claude
It works on claude.ai and in the desktop app, on every plan, even the free one.
- Go to the Humanizer page, click the green Code button, then Download ZIP. Don’t unzip it.
- In Claude, open Settings, then Capabilities, and turn on Code execution and file creation. Skills need it.
- In the left sidebar, click Customize, then Skills. Click +, then Create skill, then Upload a skill, and pick the ZIP.
- Check that the switch next to Humanizer is on.
To use it, write “Humanize this text” and paste your text underneath.
In ChatGPT
According to OpenAI’s help pages, uploading skills is offered on the Business, Enterprise and Edu plans. On those plans, here’s how it goes.
- Download the ZIP the same way, from the Humanizer page.
- In the left sidebar, click Plugins, then the Skills tab.
- Click Create, then Upload from your computer, and pick the ZIP. ChatGPT scans it before turning it on.
To use it, type @ in the conversation and pick Humanizer.
On ChatGPT’s free plan or Plus
You can get the same result with a project.
- Unzip the ZIP. You’ll find the SKILL.md file inside.
- In ChatGPT, create a project. Call it “Rewriting”, for example.
- Add SKILL.md to the project’s files.
- In the project’s instructions, write “When I paste a text, rewrite it following the rules in SKILL.md.”
Every conversation you open in that project follows the rules.
One tip
Give it a sample of how you write. Two or three paragraphs you wrote yourself, without AI, before the text to rewrite. It follows your rhythm, your words and your habits, even dashes if you use them.
