Superhuman Aims to Supercharge Your Email With an AI Assist

The startup wants to offer the fastest email experience in the world.

Lisa Lacy Lead AI Writer
Lisa joined CNET after more than 20 years as a reporter and editor. Career highlights include a 2020 story about problematic brand mascots, which preceded historic name changes, and going viral in 2021 after daring to ask, "Why are cans of cranberry sauce labeled upside-down?" She has interviewed celebrities like Serena Williams, Brian Cox and Tracee Ellis Ross. Anna Kendrick said her name sounds like a character from Beverly Hills, 90210. Rick Astley asked if she knew what Rickrolling was. She lives outside Atlanta with her son, two golden retrievers and two cats.
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Lisa Lacy
4 min read
A screenshot of some of the AI features for email from Superhuman.
Superhuman/Screenshot by Lisa Lacy/CNET

"Speed it up a little!"

That was the infamous call in a 1952 episode of I Love Lucy when Lucy and Ethel briefly had jobs on a candy factory assembly line.

But the same could be said of email app Superhuman, a 10-year-old "emerging unicorn" with its own Hollywood and entertainment industry ties, thanks to investments from Ashton Kutcher, Will Smith and the Chainsmokers.

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Estimates vary, but modern-day workers spend something like 10 to 15 hours a week on email.

"Everything we do, every feature we've ever built, whether it's AI or not," said CEO Rahul Vohra, "all revolves around this notion of how can we make you go faster, if not twice as fast, 10 times as fast?"

In fact, Superhuman was founded in 2014 to "build the fastest email experience in the world," he said.

It does this in three primary ways, which actually have nothing to do with AI. But more recently the addition of AI-based features have arguably turned the assembly line that is email into a more manageable workflow. (Too much Lucy?)

Superhuman users are "getting to their inboxes about twice as fast as before, they're responding to important emails eight to 13 hours sooner and they're each saving four hours or more every single week," Vohra said.

It's one example of how AI is changing the way we work and taking over some of the more mundane parts of our jobs so we can focus on other tasks. (Unless, of course, you like writing.)

How does Superhuman do it?

Rendering, shortcuts, split inboxes

Once you've added an email account, you can see your inbox within the Superhuman interface. Vohra explained it's worth the trouble in part because Superhuman renders messages faster than traditional email servers.

Then, thanks to command features on par with command+C and command+V in Microsoft Word, the startup is able to accelerate response times. Instead of responding to, say, a sales email by clicking reply all, moving a sender to bcc, responding to the message and cc-ing assistants and internal communications teams, Superhuman users can simply type relevant shortcuts to add pre-written introductions or email addresses.

"I can move as fast as one and two and I'm done," Vohra said. "Now I can just hit send."

Superhuman also allows you to split your inboxes into work streams based on platforms like GitHub or Google Docs, as well as on internal needs like teams, customer satisfaction surveys and applicant tracking.

Rather than having to look for all emails that require input from, say, the engineering team, you can instead siphon off these messages to a dedicated inbox and then quickly and easily respond to them in succession.

Write with AI, Auto Summarize, Instant Reply, Ask AI

About a year ago, Superhuman introduced some AI features. It uses multiple models from OpenAI, including GPT Turbo and the more recent GPT-4o model.

"What we're often doing is we are we're taking an LLM and then either training it from scratch or we're fine-tuning it based on the contents of your inbox," Vohra said.

From there, users can get help with writing emails through a feature called Write with AI, which analyzes every email you've ever sent so it can write in your voice and tone. It can also amend emails written by others on your behalf.

Another AI feature is Auto Summarize, which highlights important data and discussion points from emails, and Instant Reply, which allows you to tap on suggestions like "Great work" and then send.

Superhuman users have sent more than 4 billion emails with these last two features, Vohra says.

The most recent, Ask AI, allows you to ask for the information you're looking for in your inbox rather than using keywords to search.

"You can have this multistep conversation with the AI and get all the details," Vohra said. "Where it particularly shines is synthesizing information over a large number of emails and this can synthesize information over my entire inbox."

Next up is building AI agents that act on your behalf, not unlike Google's Project Astra.

While Vohra did not share specifics, he said Superhuman is hoping to make email more of a multiplayer experience.

"We think that's not just the future of Superhuman, but actually the future of email."

The company closed a $75-million Series C round in 2021.

This is one of a series of short profiles of AI startups, to help you get a handle on the landscape of artificial intelligence activity going on. For more on AI, see our new AI Atlas hub, which includes product reviews, news, tips and explainers.

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