Email consumes roughly 2.5 hours of the average knowledge worker's day — which is why every email client now claims an AI copilot. We spent two weeks testing three of the most visible options: Superhuman, Shortwave, and Gmail's built-in Gemini — across drafting, summarizing, triage, and the ever-important question of whether any of it actually saves time.
Superhuman: Speed as a Feature
Superhuman's AI (Ask AI, instant drafts, and its signature "write in my voice" style) is polished and fast. Its summaries of long threads are excellent — concise, correctly prioritized, and context-aware. The catch is the price (roughly $30/month) and the fact that it's most valuable for people who live in email (investors, founders, executives). For that audience, the time saved genuinely covers the cost. For a typical inbox, it's luxury hardware for a commuter car.
Shortwave: The AI-First Gmail
Shortwave (built on a Gmail-like foundation, with AI-native design and optional Gmail sync) leans hardest into automation: automatic inbox triage, thread summaries, one-click task extraction, and AI-scheduled follow-ups. Its standout is the "AI keyboard" drafting experience and the auto-categorization, which consistently routed the noise (newsletters, alerts) out of the way. Free tier exists; Pro runs about $14–19/month. Best for people who want AI triage without leaving the Gmail ecosystem.
Gmail + Gemini: The Free Baseline
Google's built-in Gemini in Gmail — available to Workspace and Google One AI subscribers — now handles summarize, draft, and "help me write" directly in your existing inbox. It trails the dedicated clients on thread awareness and style matching, but it's free (with your subscription) and requires zero migration. For most people, this is the 80% solution: good enough drafting and summarizing, no new app, no new subscription line item.
Head-to-Head Test Results
- Drafting quality: Superhuman = Shortwave > Gmail Gemini. The dedicated tools match tone and tighten prose noticeably better.
- Thread summarization: Superhuman ≈ Shortwave > Gmail. Both dedicated tools handle 40-message threads with accurate priority extraction.
- Inbox triage/automation: Shortwave wins outright — its auto-categorization and follow-up reminders are the deepest.
- Cost & friction: Gmail wins — zero extra setup for most users, bundled with existing AI subscriptions.
- Privacy consideration: all three route mail through their AI processing — worth checking the settings page for your organization's compliance needs.
Who Should Buy What
Choose based on your relationship with email:
- Heavy inbox (3+ hours/day): Superhuman — the speed and thread summaries compound into real hours.
- Medium inbox, want automation: Shortwave — best AI triage-to-zero experience outside of full-blown enterprise tools.
- Light-to-medium inbox: stick with Gmail + Gemini — it's already paid for and covers 80% of the value.
The Bottom Line
AI email tools are genuinely useful — not hype — for drafting, summarizing, and triage. But the marginal gain from paying $30/month over the free option is only worth it if email is your primary work surface. Our recommendation: max out Gmail's Gemini first, then graduate to Shortwave if you want automation, and only reach for Superhuman if your inbox is genuinely your office.