Superhuman vs Shortwave: two AI email clients, compared fairly

How Superhuman and Shortwave differ in use

Superhuman Mail is built around speed. Nearly every action has a keyboard shortcut, Split Inbox divides mail into tabs, and AI Auto Labels separate marketing, cold pitches, and social updates. It adds AI drafts in your voice, reminders, Send Later, opt-in read statuses, calendar booking, and team comments. Reviewers say the shortcuts take a week or two to learn and then pay off.

“Split Inbox is the feature I'd miss most if I switched away; separating VIPs, calendar, and news from everything else means I actually see what matters first.”Shai D., G2, July 2026

Shortwave is built around its AI assistant. You can ask it to find a thread, summarize an exchange, draft a reply, or schedule a meeting, and on higher plans write AI filters in plain language that label, archive, or star new mail. Splits, Bundles, and delivery schedules group lower-priority mail. Its plans differ mostly in AI usage quotas, search history, and the number of AI filters.

“it reads all my past emails and can interpret them in my style, not the formatting of regular LLMs exposed to the whole world.”Verified User in Consulting, G2, May 2025

Superhuman vs Shortwave pricing, trials, and refunds

Shortwave is cheaper to start. Its free plan is permanent, and Pro is $18 per seat a month, though AI filters start on Business at $30. Premier ($45) and Max ($120) buy more AI usage and stronger models. Shortwave bills monthly only. Superhuman Mail has no free plan: Starter is $30 per member a month or $25 billed annually, and Business is $40 or $33 billed annually.

Shortwave offers a 14-day trial of its paid plans and a full refund if you ask within 14 days of a payment. Superhuman publishes no standard Mail trial, though some of its pages show a promotional free month, and its Terms say payments are non-refundable; its annual-plan help article does offer to refund unused time on request. Cancelling and paying up front come up in critical reviews of both.

“It lures you to pay upfront with no trial, no refund”Sebastian Zontek, Trustpilot, August 2026

“eventually didnt save time so I tried to cancel but even that couldnt as missed the refund policy”Yonatan S., G2, September 2025

Email providers and platforms

Superhuman supports Gmail and Microsoft 365 hosted accounts and nothing else, so iCloud, Yahoo, and other IMAP accounts are out. Shortwave requires a Gmail or Google Workspace account; its docs say Microsoft 365 and Exchange are not supported and give no timeline. Yahoo, iCloud, Fastmail, and Zoho can be forwarded into Gmail and sent from; Outlook.com can only be forwarded in. Both run on Mac, Windows, the web, iOS, and Android. Superhuman has no unified inbox across accounts, while one Shortwave seat covers all the accounts you sign into on a device.

“Finally, the lack of a unified inbox across multiple accounts can slow things down when you’re juggling several projects at once.”Igor S., G2, August 2026

Privacy and how each uses your mail for AI

Both read full message content, since both display your mail and run AI on it. Superhuman's privacy policy (effective July 6, 2026) says it uses collected information to train its own AI models and lets you control whether your user content is used through account settings; it says it contractually bars its outside AI providers from training on your data. In 2019, after criticism that its read receipts logged recipients' locations, it removed location logging and made read receipts opt-in (TechCrunch, July 3, 2019).

Shortwave's security guide says it stores data in Google Cloud, encrypted at rest and in transit, and that its only other sub-processors are OpenAI, Anthropic, and Pinecone. It says most AI work runs on open-source models on its own hardware, while its pricing page names Anthropic's Claude models for each AI level, and it says your data is never used to train third-party models. Neither company sells user content, by its own account.

Who makes each one

Superhuman Mail was founded in 2014 by Rahul Vohra. Grammarly bought it in July 2025 and renamed itself Superhuman in October 2025, so Mail is now one product in a suite with Grammarly, Docs (formerly Coda), and Go, owned by Superhuman Platform Inc. in San Francisco. Shortwave is made by Shortwave Communications, Inc., founded by Andrew Lee and Jonny Dimond, who worked on Firebase at Google; TechCrunch reported a $9M Series A in February 2022. The founders' newer product, Tasklet, raised $20 million in April 2026 according to investor USV, and Shortwave calls it a sister product.

Superhuman vs Shortwave reviews, like for like

G2 is the platform where both have enough recent reviews to compare. In our pull of each product's 50 most recent G2 reviews, Superhuman Mail averaged 4.71 (March to September 2026) with 42 labeled incentivized, and Shortwave averaged 4.54 (August 2022 to September 2025) with 47 incentivized. Both samples are mostly incentivized, so the comparison is fair on that count, but Shortwave's reviews are older, most of them from 2022 and 2023, and describe an earlier version of the app.

On Trustpilot, Superhuman's unclaimed profile has 12 reviews, all unprompted, averaging 1.5, with complaints about cancelling and promotional email sent in the user's name. Shortwave has no Trustpilot reviews, so there is nothing to set against it.

“After paying for a business account, I found out they altered my signature, so that every email I sent contained a superhumane ad.”Bork Morfaw, Trustpilot, December 2025

If you'd rather keep your current email app

Both Superhuman and Shortwave ask you to move your email into a new app and limit you to Google (and, for Superhuman, Microsoft). If what you want is a cleaner inbox in the app you already use, SaneBox is a different kind of tool: a server-side filter that moves unimportant mail into folders, learns from what you open and answer, and works with Gmail, Microsoft 365, iCloud, Yahoo, Fastmail, or any IMAP account. It costs from $9.49 a month and has no AI assistant or free plan, but its 7-day trial needs no card. We compare it with each one in SaneBox vs Superhuman and SaneBox vs Shortwave.