Hundreds of AI text "humanization" tools are appearing to help edit sentences more naturally, imitating human writing style.

Huong Ly, a communications officer at a technology company in Hanoi, paused for a long time before a post about a tool that could make AI-generated text more natural. As a "follower" of ChatGPT, Gemini and Claude, she wants to learn more applications that can create content similar to human writing for use at work.

Such tools are called AI Humanizers. According to Toolify, as of September, the platform recorded more than 200 tools under the AI ​​Humanizer category. Promoted products have the ability to transform text created by ChatGPT, Claude or Gemini into content with a more natural tone.

Usage is also quite simple. For example, with Undetectable AI, StealthWriter or WriteHuman, users just need to paste the text, select editing mode and get a new version back.

Most tools work for free but are limited in number of times or length, then charge a monthly fee or usage amount. For example, StealthWriter allows free accounts to process up to 10 times per day, no more than 1,000 words at a time; Paid plans start at $20 per month.

Some AI Humanizers are also introduced with the ability to bypass AI recognition systems. Turnitin, the developer of the anti-plagiarism platform, calls this AI Bypasser. The company says the past two years have seen a rise in tools that help disguise AI-generated text.

Annie Chechitelli, Turnitin's product manager, said earlier this year that about 150 tools in this group had been identified. They had to release a software update in August 2025 to detect edited text using AI Bypasser.

Regarding effectiveness, research by expert Samantha R. Rosenthal and colleagues, published in September, shows that text editing with AI Humanizer or human intervention significantly reduces the effectiveness of AI detection tools.

The group tested 5 tools with 500 academic passages. As a result, they distinguish very well between text written entirely by humans and generated by AI. However, the effectiveness is greatly reduced when the text is processed through AI Humanizer or has additional human adjustments.

Le Thanh Hung, administrator of the Popular AI community with more than 600,000 members, said AI users in Vietnam, including students and researchers, have begun to know and use AI Humanizer, but the number is not large. The reason is that these tools mainly work well with English, while "specialized tools for Vietnamese are few and have limited processing capabilities".

Sharing with VnExpress, Dr. Dang Minh Tuan, Vice President of CMC and Director of Research and Application CMC ATI, evaluated AI Humanizer tools that also use large language models (LLM) similar to popular AI today.

The difference lies in how they edit the output. AI documents often have a neat structure and relatively uniform sentences. AI Humanizer seeks to change writing style, create differences in expression, and even add some common errors in writers to make the text look more natural.

However, according to him, users today do not necessarily use separate tools. They can issue commands to ask popular AI models themselves to write in a more natural voice, avoiding mechanical expressions to get the same results.

Duc Viet, head of marketing at a business with more than one million users, said he often uses Claude and ChatGPT to support work. When he needs to edit natural text, he asks these chatbots to change the wording.

According to him, AI Humanizer only solves the content stage, which is a small and low-cost part of the marketing process. For common editing requirements, popular AI models can respond well.

For Huong Ly, after a while of trying to test AI Humanizer, she decided to go back to find ways to optimize familiar AI tools, because after the free trial period expired, the application required a fee of 5 USD per month for a 10,000 word package, which was beyond the affordability of a marketer like her.

Zhong Dat