From signing my emails with “bet” instead of “best” or sometimes writing “felt” instead of “left”, living with dyslexia and choosing a career that requires me to write on the daily has turned typos into my biggest nightmare. After all, I’ve been taught that typos signal carelessness, unprofessionalism, or worse—lack of talent altogether. But as AI makes life seemingly more perfect, tiny errors are also signatures of our humanity—and that we put actual care into what we wrote instead of mindlessly relying on an LLM.
Well, now there’s an AI tool to that will pen a perfectly imperfect email. Sinceerly (yeah, it’s spelled that way) is an extension that makes slop emails sound more human—mistakes and all.
Ben Horwitz, an investment partner at venture capital firm Dorm Room Fund and student at Harvard Business School, created Sinceerly. Annoyed with so many emails obviously sounding like AI, Horwitz saw an opportunity to “hold up a mirror” to our complicated relationship with technology. Our typos, ourselves?
It’s satire, of course. “If we are using AI to write, then in this moment, can we use AI to un-AI our own writing?” he tells Fast Company. “That’d be funny.”
So for the last month, he used his time in between classes to code what he now calls the “anti-Grammarly.” (The misspelled name is both on brand and allowed Horwitz to purchase the domain for cheap; he is a student, after all.)
Sinceerly, which Horwitz shared on X this week, is available as a browser extension, straying not too far away from Grammarly’s interface. You can pick from three levels of edits: subtle, human, or CEO. The latter nods to the final boss of typos. Brevity and misspellings have become somewhat of a status symbol in business. CEOs are simply too busy and too important to care about punctuation, after all.
Here’s how it works: The tool rewords a long and jargony AI paragraph and condenses it per each level. For instance, a “subtly” edited five-line paragraph will condense the phrase into three lines. “Human” takes it further by adding more slang and abbreviations, and trimming even more words. CEO mode goes completely rogue:
“think we should connect. potential here. quick call this week? lmk
Sent from my iPhone”
Cue the copy editor panic attack.
But Sinceerly actually worked. Horwitz sent emails to five Fortune 500 CEOs, four of whom replied.
The test, which he admits is not entirely rigorous, proved two things: one, Sincereely did indeed turn AI slop into emails that maybe CEOs would respond to; and two, CEOs actually do write like that. Each email he received was under ten words and two had typos; and one CEO called him Larry.
While Horwitz created the tool as somewhat of a joke, many believe that bringing humanity back into the inbox might be a powerful business move.
“An email marketer told me once that when they started putting typos in subject lines, open rates went up by like 40%, because people assumed a human wrote it,” New York Times tech columnist Kevin Roose replied to the announcement via X.
There’s also a paradox within this anti-AI tool: Horowitz needed AI to build it. Using Claude and Chat GPT allowed him to deploy the tool in a month. There’s a lesson in this, he says: “Where AI comes in is not the idea, but, the idea to execution timeline feels crunched to me. That’s where I feel like it’s been most helpful.”
Horwitz is not unaware of the contradiction. “I want to live in a world where people still can distinguish AI writing from human writing, which is why it’s so ironic that I built this thing,” he says.
And still, whether people online treat the project as a tool—which Horwitz is charging $4.99 a month to use after a 3-email free trial—or just as a quick joke, its fast virality underscores a larger conversation. In a world fatigued and frustrated with AI, a human touch is valuable. As one user on X puts it: “Stop being ashamed of typos, embrace them, It’s one of the last things we have to ourselves.”
