--- title: "New Browser Plugin Adds Typos to Your AI-Generated Emails to Make Them Look Real" description: "A new browser plugin intentionally adds typos and other grammar mistakes to emails to make them sound less like AI." date: "2026-04-26" modified: "2026-04-26" authors: - name: "Victor Tangermann" job_title: "Senior Editor" link: "https://futurism.com/authors/victor" url: "https://futurism.com/artificial-intelligence/browser-plugin-typos-ai-generated-emails" categories: - "Anthropic" - "Artificial Intelligence" - "Ethics" --- # New Browser Plugin Adds Typos to Your AI-Generated Emails to Make Them Look Real ![A new browser plugin intentionally adds typos and other grammar mistakes to emails to make them sound less like AI.]() *Getty / Futurism* The advent of large language model-based writing tools have given lazy or unconfident writers incredible new shortcuts that can spit out everything from glossy work emails to crispy school papers. The problem, of course, is that bosses and teachers around the world quickly got wise to the phenomenon — and as a result, any text that feels too tidy and polished has started to arouse suspicion. Now, in an effort to reintroduce some of the messiness of human writing — and hide our AI addiction — venture capitalist Ben Horwitz used Anthropic's Claude AI to vibe code a browser plugin that does something that would have seemed preposterous just a few years ago: intentionally adding typos to emails. "I made the anti-Grammarly," he [bragged](), referring to a popular, AI-powered spelling and grammar checker. "Mess up your emails with AI." The cleverly named software, dubbed "[Sinceerly]()," promises to wreak some controlled havoc on overly coiffed emails, from undoing capitalization at the beginning of a sentence to the introduction of glaring typos that would make any copy editor's eye twitch. (We'd advise against trying it out yourself until you get to the caveat at the end of this piece, though.) You can even choose the degree of severity for the errors, ranging from "Subtle," to "CEO," a tongue-in-cheek jab at high-ranking executives who are known for how little care they put into their communications. It'll even go as far as to append the phrase "sent from my iPhone." The browser plugin was inspired by our growing obsession with [often-overbearing spellcheckers](). "I am a terrible typist, naturally, and lightly dyslexic," Horwitz [told *Business Insider's* Katie Notopoulos](). "It would take me so long in my first job straight out of college to write emails and make sure there were no typos and everything." "When Grammarly came around, it was like, 'Oh, OK, this is pretty good for me.' But now my email inbox is filled with AI slop," he added. "I tested Sinceerly by cold emailing 5 Fortune 500 CEOs," Horwitz bragged in a [Thursday tweet](). "Four replied. Of those replies, each was under ten words. Two replies had typos." In Notopoulos' testing, the tool turned a polite email draft informing her boss that she's hoping "to have a sandwich for lunch today" into a messier "writing to confirm lunch plans" when shifted into "CEO" mode. However, in our own testing, the vibe-coded project appears to have succumbed to bugs after *BI* published its piece, with an error message rendering it largely useless. In other words, for now, you're stuck relying on your own human flaws for less AI-sounding work emails. **More on spellcheckers:** [*CEO Confronted Over Using AI to Clone Real People Without Their Consent*]() ## Author I've been at Futurism since 2017, where my role has evolved to encompass design, writing, and increasingly editing. I've always been fascinated by space exploration and advanced transportation, which I've leaned into by interviewing luminaries in those fields while closely following the dimensions of policy and regulation that allow next-generation projects to succeed -- or, sometimes, to fail. I'm also keenly interested in the effects of generative AI on society, policies, and democratic institutions, as well as clean energy, physics and biology, and the vagaries of tech leadership. My work for Futurism has been cited by publications including Ars Technica, Gizmodo, PC Magazine, Jalopnik, Fox News, and the New York Post. I spent my childhood living in locations including Manila, the Philippines, and Geneva, Switzerland, attended McGill University, and now live in Toronto, Canada. Before Futurism I worked at AskMen and a small photography studio. In my free time, I'm an avid gardener, foodie, and craft beer lover, as well as a maker of artisanal hot pepper sauces. I have a magnificent dog named Freida. ### Author social links [Bluesky]()