Quick Verdict
Superhuman is still the fastest way to burn through a heavy inbox if you live in Gmail and can stomach $30/month. Shortwave is the one I’d actually hand to a team, especially if you want AI drafts that multiple people can poke at before they go out. Spark is the “good enough for most humans” option and the free tier is genuinely usable, not a crippled demo. For the broader AI productivity toolkit, see our AI productivity tools roundup.
None of these are magic. The AI drafts still need editing, the summarization still misses things buried in 40-message threads, and “inbox zero by 10am” is a function of discipline, not software.
How We Tested
We used each of these for real work over about three months — not a scripted benchmark. Two of us on the review team ran them as our primary email client in rotation, and we leaned on a handful of other folks (a VP of sales, a support lead, a freelance consultant) to get a read on workflows other than ours. No automated test harness, no synthetic email corpus, no “10,000 emails in a sandbox” — just daily use, screen recordings of processing sessions, and notes on what broke.
Where we cite numbers below, they’re either from the vendor’s own docs, publicly stated pricing, or our rough counts from actual usage. When something is a gut feel, we’ll say so.
At a Glance
| Superhuman | Shortwave | Spark | |
|---|---|---|---|
| Monthly (individual) | $30 | $7 | Free / $5 Premium |
| Team pricing | $30/user | $9/user | $5/user |
| Providers | Gmail/Workspace only | Gmail, Outlook, IMAP | Everything incl. iCloud/Yahoo |
| Keyboard-first | Yes, aggressively | Partial | Minimal |
| Offline | No | Yes | Yes |
| Team collaboration | Light | Strong | Basic |
| Setup friction | 30–45 min onboarding | ~15 min | ~5 min |
| Free trial | None anymore | 14 days | Free tier forever |
Rough impression, not a score: Superhuman feels the most polished and the most expensive for what it does. Shortwave feels like the product most actively shipping new stuff. Spark feels like it’s been quietly reliable for years and the AI was bolted on later.
Superhuman: Fast, Expensive, Gmail-Only
$30/month per user
Superhuman’s pitch hasn’t really changed: keyboard shortcuts for everything, opinionated UI, every animation tuned to feel instant. The AI layer they’ve built on top of that is good, but it’s not the reason to buy Superhuman. The reason to buy Superhuman is that triaging email with it feels like playing a fighting game once you learn the inputs.
What the AI actually does
Draft generation. You hit a key, it writes a reply in something resembling your voice. After a couple of weeks it genuinely started matching how I phrase things — not because of magic, but because it’s clearly doing few-shot conditioning on your sent folder. For routine replies (scheduling, acknowledgments, short answers) I was sending the first draft with minor edits maybe 60-70% of the time. For anything with nuance — pushing back on a client, delivering bad news, negotiating — the draft was a starting point at best. Sometimes worse than starting from scratch because you end up fighting its tone.
Triage / priority labeling. It sorts incoming mail into “important,” “calendar,” “news,” and so on. For the VP of sales who tested it, this was the killer feature — she stopped scanning the full inbox every morning and trusted the priority view. That trust took about a week to build. The first few days she kept double-checking and caught two or three things the AI had misclassified as low-priority. After that, almost nothing slipped.
Thread summaries. Long threads get a few-sentence recap and extracted action items. Works well on threads up to maybe 15 messages. Past that it starts dropping context, especially when the same topic has been argued across multiple replies. I wouldn’t rely on the summary alone for anything contractually important.
Instant Reply / one-click responses. These are fine. Nothing revolutionary — Gmail’s Smart Reply has done this for years. Superhuman’s versions are more context-aware but the gap is narrower than their marketing suggests.
The actual problems with Superhuman
- Gmail only. If your company uses Outlook or Microsoft 365, you’re done reading this section. There’s no workaround.
- Thirty dollars a month. It’s not that it isn’t worth it — for the right person it absolutely is. It’s that the right person is a narrow slice: someone processing 100+ emails a day whose hourly value is high enough that saving 20 minutes matters. For a normal knowledge worker checking email a few times a day this is wild overspending.
- The learning curve is real. The keyboard shortcuts are the whole point, and you won’t feel fast for at least a week. Most people I’ve seen try Superhuman bail before they hit the payoff curve.
- Team features are thin. You get delegation and shared threads, but nothing like a real shared inbox. If more than one person needs visibility into the same mailbox, look elsewhere.
- No offline mode. In 2026 this still surprises me every time my plane Wi-Fi dies.
- The free trial is gone. They removed it in late 2025 and now you have to commit to a paid month to evaluate it. That’s a real friction point.
Buy it if: you live in Gmail, process a heavy volume daily, and the speed of triage directly affects your income or sanity.
Shortwave: The One I’d Actually Put On a Team
$7/month individual, $9/month per seat for teams
Shortwave is the product I’ve been most impressed by over the last year. It’s clearly built by people who understand that email is a team sport for a lot of companies, and the collaborative features aren’t bolted on — they’re the core design.
The features that matter
Shared inbox and team assignments. You can assign a thread to a teammate, leave internal notes that don’t get sent to the customer, and see who’s working on what. This sounds mundane until you’ve watched a support team try to do it in raw Gmail with color-coded labels and a shared spreadsheet.
AI drafts you can review before sending. This is the feature I’d highlight if I were selling Shortwave. A junior rep drafts a reply with AI assistance, a senior rep sees it in the shared view, leaves a comment, the draft gets tweaked, and then it goes out. For anyone who has ever had to un-send something embarrassing, this workflow is valuable.
Cross-thread clustering. Shortwave groups related conversations even when subject lines drift. This is subtly great for project-based work where the same discussion spans five different email chains. It’s not perfect — I saw it miscluster occasionally when two projects shared the same participants — but it’s closer to “right” than any other clustering I’ve used.
Summarization and action-item extraction. Comparable to Superhuman for short threads, a bit worse on really long ones. Fine for day-to-day use.
Multi-provider. Gmail, Outlook, IMAP. This matters a lot for mixed environments or for individuals whose personal and work accounts live on different platforms.
What’s not great
- Slower feel than Superhuman. Not slow in an absolute sense — the app is responsive — but the keyboard-driven flow is nowhere near as aggressive. If you’ve internalized Superhuman’s shortcuts, Shortwave will feel sluggish even though it isn’t.
- AI draft quality is a notch behind Superhuman. My subjective take: I accepted fewer first drafts verbatim. Still workable, but I edited more.
- Delivery tracking is absent. Some people love knowing when a recipient opens their email; some people find it creepy. If you’re in the first camp and relying on it for sales follow-ups, you’ll miss it here.
- Individual plan is a bit stripped down. Some of the best features — the collaboration ones — obviously only matter with a team, but the individual plan also carves out a few things that aren’t strictly team features. Worth checking the pricing page before committing.
- Support is smaller-scale. Response times are fine but you’re not getting a dedicated account manager unless you’re at enterprise scale.
Buy it if: you run a team that shares any kind of external email workload (sales, support, partnerships, hiring). At $9/seat this is an easy yes for most small teams.
Spark: Competent and Free Enough
Free / $5 per month Premium / $5 per user team plan
Spark is the tool I’d recommend to most people who asked me “should I pay for an email app?” because the answer for most people is “no, but try this one.”
What you get
A clean email client that works across every provider including the weird ones (iCloud, Yahoo, custom IMAP). AI drafting that covers the basics. Smart notification filtering that learns what you actually care about. A big template library — something like 500 templates, per their docs — organized by use case. Quick reply chips that handle the “yes, sounds good” and “thanks, received” replies in one tap.
The free tier is real. Not a 7-day trial, not a feature-crippled teaser. It’s the client most people would be happy using indefinitely. Premium adds nicer AI features, removes the display ads, and gives you some extra customization.
The honest limitations
- The AI is the weakest of the three. Drafts are more generic, tone matching takes longer, and it fumbles nuanced replies more often than Superhuman or Shortwave. If I had to put a finger on it, Spark’s AI feels like a layer on top of standard inference-time prompting without a lot of user-specific fine-tuning. Fine for common cases, less good for anything that needs to sound like you.
- Smart notifications occasionally miss important emails. This was my biggest frustration. During testing I had at least two messages I’d have wanted pinged that got filtered into the quiet pile. You end up still checking manually, which defeats some of the point.
- Ads in the free version. They’re not obtrusive but they exist. $5/month kills them.
- Team features are basic. If you genuinely need collaborative email, Shortwave eats Spark’s lunch here. Spark’s team plan is more “individual accounts with some shared templates” than a real shared inbox.
- Support is email-only. Not a dealbreaker for a free product but don’t expect same-day fixes when something breaks.
Buy it (or don’t pay for it) if: you process a modest amount of email, you don’t use Gmail exclusively, or you just want one nice client that works across your five accounts.
Three Scenarios, Three Different Winners
High-volume exec. The VP of sales who tested for us burned through roughly 200 emails a day. Superhuman was unambiguously the right tool — the speed difference is real, and Smart Triage pulls its weight when you genuinely can’t afford to eyeball every message. Shortwave and Spark worked but took visibly longer to get through the pile.
Five-person support team. This was the clearest win for Shortwave. The shared draft review workflow caught two potential customer-facing mistakes during the test period. Superhuman is individually faster but doesn’t solve the team coordination problem. Spark’s collaboration was too light to matter at this size.
Freelance consultant, ~50 emails a day. Spark, easily. Superhuman at 50 emails/day is burning money. Shortwave’s individual plan at $7 is defensible, but if you’re a solo operator and not spending meaningful chunks of your day in email, the free tier does the job.
Pricing Reality Check
Superhuman’s annual cost shakes out to $360/year per person. Shortwave individual is $84/year. Spark is free or $60/year for Premium. For a team of 10, you’re looking at roughly $3,600, $1,080, or $600 per year respectively.
The Superhuman ROI pitch — “it saves you X minutes a day so it pays for itself at $50/hour” — is technically true but only if you actually recapture that time into higher-value work. In practice most people fill the time with more email. Judge accordingly.
Privacy and Security
All three publish the usual things: encryption in transit and at rest, opt-outs for model training, compliance with the usual certifications. Superhuman’s Gmail-only nature actually tightens its security story — fewer providers, fewer attack surfaces. Shortwave has SSO and admin controls that matter for bigger orgs, plus a European data region option if GDPR scope matters to you. Spark supports a local-processing mode for some AI features, which is nice if you’re handling anything sensitive.
If you’re in a regulated industry, don’t take any of our word for this. Read each vendor’s actual data processing agreement and check what happens to your email content at inference time — whether it’s sent to a third-party model provider, whether it’s logged, whether it’s retained.
My Actual Recommendation
Start with Spark’s free tier. Seriously. Use it for two weeks. If you find yourself wishing AI drafts sounded more like you, or you’re frustrated that you can’t triage fast enough, or you’re on a team and you keep stepping on each other’s replies, then you have a real reason to upgrade.
If “faster triage” is the pain, try Superhuman — but only if you’re on Gmail and genuinely process a lot of email. If “team coordination” is the pain, Shortwave is the obvious pick. If neither of those is the pain, you don’t need to spend money on an email client. For project management that complements your email workflow, see our AI project management tools comparison.
One broader point: AI email assistants in 2026 are much better than they were two years ago, but they’re all still working against the same underlying problem — email is a medium that rewards careful, human-written communication, and automating the human part has limits. These tools save time on the easy 60% and politely stay out of the way on the hard 40%. Anyone selling you more than that is selling you a demo, not a product. For AI writing tools that produce the content you then send via email, see our best AI writing tools comparison.
FAQ
Is Superhuman worth $30/month? Only if you’re in Gmail all day and process 100+ emails daily. Otherwise no.
Does Superhuman work with Outlook? No. Gmail and Google Workspace only. This has been the case for years and shows no sign of changing.
Can I switch clients without losing anything? Yes. All three connect to your provider via IMAP/standard APIs. Your mail lives on the provider’s servers. Switching is connect-new, disconnect-old.
How reliable are AI-drafted replies? Good for short, routine responses across all three. Progressively less reliable as the email gets more nuanced. Always read before sending. Don’t trust any of them with high-stakes communication without editing.
Mobile? All three have real iOS and Android apps. Superhuman’s mobile parity is the closest to desktop. Shortwave and Spark mobile are good but you’ll feel a few things missing.
Do they read my emails? Yes, that’s how they work. All three state they don’t use your content to train models by default. If this matters to you, read the actual privacy policies, not the marketing pages — they differ in the details that might matter to your compliance team.
Best support? Superhuman for high-touch onboarding. Shortwave for responsiveness and documentation. Spark for self-serve. Matches the price points.
Recommended Tools & Resources
If you’re exploring this topic further, these are the tools and products we regularly come back to:
Some of these links may earn us a commission if you sign up or make a purchase. This doesn’t affect our reviews or recommendations — see our disclosure for details.