May 12, 2026

Superhuman vs Shortwave vs Carly (2026): Which AI Email Tool Wins?

All three tools promise to fix your inbox. They do it in completely different ways.

Superhuman makes you faster. Shortwave makes the inbox smarter — AI search and summaries inside a Gmail-only client. Carly does both and takes work off your plate: you can ask her “who do I need to respond to?” the same way you’d ask Shortwave, but she’ll also draft, send, schedule, and update your CRM autonomously.

Here’s how to choose.

At a Glance

	Superhuman	Shortwave	Carly
Core model	Faster email client	Smarter Gmail client	AI assistant + agents over email
Gmail	Yes	Yes	Yes
Outlook	Yes	No	Yes
Free tier	No (trial)	Yes (limited)	No (trial)
Starting price	$25/mo	$7/mo	$35/mo
AI search & triage	Auto Labels	Natural-language search, AI Q&A	Ask Carly anything over email
AI replies	Auto Drafts (your voice)	AI-assisted drafting	Drafts + sends autonomously
Takes action across tools	No	Limited (Tasklet)	200+ integrations across 40+ categories
Removes work from your plate	No (speeds it up)	No (faster processing)	Yes

Superhuman — Best for Speed-Obsessed Power Users

Built around one premise: the fastest possible email experience. Keyboard shortcuts for everything, split inbox, snooze, send later, undo send. Grammarly acquired Superhuman in 2025 and the AI layer has expanded since — Auto Drafts writes follow-ups in your voice, Auto Labels classifies email, summarization handles long threads.

Best for: People with high-volume substantive email who want to process it 2–3× faster.

Limitations: No free tier. The model assumes you are still reading and replying to everything — it just makes that faster. If repetitive workflows eat your day, Superhuman doesn’t remove them.

Pricing: From $25/month (annual) or $30/month; Business from $33/month.

Shortwave — Best for AI-Augmented Gmail

Replaces the Gmail interface with something smarter. Natural-language search (“emails from last month about the Acme deal”), AI thread summaries, automatic bundling, and an AI assistant you can ask questions about your inbox. Built by ex-Inbox-by-Gmail engineers. Tasklet, launched in early 2026, adds limited cross-tool automation.

Best for: Gmail users who want AI search and summarization without leaving the inbox.

Limitations: Gmail only — no Outlook. Pricing tiers split AI usage in ways that frustrate some users. Like Superhuman, Shortwave makes the inbox smarter but doesn’t take work off your plate.

Pricing: Free (limited); paid from $7/seat/month; Business from $24/seat/month.

Carly — Best for Actually Removing Email Work

Carly is structurally different. It’s not an email client — it’s an AI assistant and agent platform that works through email. Two modes overlap with the other tools but go further:

Ask Carly anything. Email her “who do I need to respond to today?” or “summarize what’s happening on the Acme thread” or “what did Sarah send last week about the budget?” — same kind of natural-language inbox Q&A Shortwave offers, but Carly works in Gmail and Outlook, and her answer comes back as an email reply you can act on from any device.

Then let her do the work. “Draft replies to the three most urgent ones.” “Book a time with that prospect for Tuesday.” “Log this thread to HubSpot and create a follow-up task in Linear.” Carly’s agents have their own email addresses, custom instructions, and memory. They draft, send, schedule, update CRMs, create tasks, upload files — autonomously, across 200+ integrations (HubSpot, Salesforce, Attio, Google Calendar, Zoom, Slack, Asana, Linear, Notion, Google Drive, and more).

Best for: Professionals whose inbox is a mix of substantive correspondence and repetitive workflows (scheduling, intake, follow-ups, CRM logging) they’d rather not touch.

Limitations: $35/month entry price is higher than Shortwave’s $7 tier. Not the right tool if you just want a snappier inbox UI — Carly’s value is in the work she removes.

Pricing: From $35/month.

Side-by-Side on Real Workflows

“Who do I need to respond to?” Shortwave: ask the in-app assistant. Carly: email her the question; reply lands in your inbox. Superhuman: not really its model.

Replying to a long thread: Superhuman’s Auto Drafts writes in your voice. Shortwave suggests replies. Carly reads the thread, decides whether to respond, drafts and sends — without you opening the email.

Booking a meeting: Superhuman and Shortwave speed up your reply. Carly’s scheduling agent reads the request, checks your calendar, proposes times, handles the back-and-forth, and sends the invite.

Logging to CRM: Superhuman (Business plan) shows context inline. Shortwave triggers actions via Tasklet. Carly extracts fields, creates or updates the record, notifies you on Slack — autonomously.

The pattern: Superhuman and Shortwave optimize how fast you act on email. Carly answers your questions the same way Shortwave does, and then actually does the work.

Which One to Use

Superhuman if your inbox is mostly substantive correspondence you want to write yourself, faster.

Shortwave if you live in Gmail and want AI search and summarization without leaving the inbox. Skip it if you need Outlook.

Carly if you want both the natural-language inbox Q&A and an assistant that takes action — drafting, scheduling, CRM updates, follow-ups — on your behalf. Works in Gmail and Outlook.

Some users run Superhuman or Shortwave for the email they write themselves, and Carly for the workflows they don’t want to touch. The combination handles both.

More on AI email tools: Best AI email assistants · Best AI email agents · Superhuman alternatives · Shortwave alternatives