MorningZero vs Superhuman vs Shortwave vs Spark vs Missive vs Gmail: what each costs and what its AI actually meters (checked August 2026)
Most comparisons of AI email clients are useless because they compare marketing pages. Everyone claims AI, so “has AI” tells you nothing. What actually separates these products in August 2026 is narrower and more boring: what you pay per seat, and which parts of the AI are rationed.
So this post does two things. It puts the real prices side by side — read off each vendor’s own pricing page on 5 August 2026 — and then says exactly what each tool meters, in the vendor’s own units.
Prices change. Every figure below has a link and a date. If you’re reading this months later, click through before deciding anything.
What each seat costs
| Product | Free plan? | Entry paid tier | Next tier | Source |
|---|---|---|---|---|
| MorningZero | Yes — Free, $0 | Pro $18/mo ($14/mo annual) | Team $12/seat ($10 annual) | MorningZero pricing |
| Superhuman | No | Starter $30/seat/mo ($25 annual)* | Business $40 ($33 annual)* | superhuman.com/pricing |
| Shortwave | No — 14-day trial | Business $30/seat/mo | Premier $45, Max $120 | shortwave.com/pricing |
| Spark | Yes — Free, $0 | Plus $10/user/mo ($120/yr) | Pro $20/user/mo ($240/yr) | sparkmailapp.com/pricing |
| Missive | Yes — free plan, no card | Starter $14/user/mo | Productive $24, Business $36 | missiveapp.com/pricing |
| Gmail | Yes — free for personal use | Gemini in Gmail requires a paid Workspace tier | — | Workspace pricing |
* Superhuman’s pricing page renders client-side, so those two figures come from third-party trackers checked on 5 August 2026 (usecarly, Morgen) rather than from the page itself. Treat them as indicative and confirm on Superhuman’s site.
Missive’s annual discount is 20% off those monthly rates. Spark bills annually as a lump ($120 and $240), which works out to about $8.25 and $16.58 per month.
What each one rations
This is the part that decides whether the AI is something you use freely or something you budget around. The units below are the vendors’ own.
| Product | What’s metered | Published limits (5 Aug 2026) |
|---|---|---|
| Shortwave | AI requests per day, threads per search, number of AI filters | Business: “roughly 150–300 Standard intelligence AI requests per day”, max 50 threads per AI search, 3 AI filters, 5 years AI search history. Premier: 2× usage, unlimited history, 100 threads, 10 filters. Max: 6× usage, 150 threads, 50 filters |
| Spark | AI credits, plus meeting notes counted separately | Plus: 40 AI meeting notes/month plus a monthly credit quota. Pro: unlimited meeting notes, monthly credit allowance. Free: limited preview of the AI assistant, no add-ons |
| Missive | AI credits, or bring your own key | ”Missive AI credits or BYOK”, multi-provider (Anthropic, OpenAI, Gemini). No per-request limits published on the pricing page |
| Superhuman | Not published per-request | The pricing page states no AI request limits |
| Gmail | Tier-gated rather than metered | Gemini features arrive with the paid Workspace tiers |
| MorningZero | On-demand reasoning only | Ask Zero chat, summaries and drafting spend credits. Labeling incoming mail does not |
Shortwave deserves credit here. Publishing “150–300 requests per day” is more honest than the industry norm of saying nothing, and it tells you the shape of the product: the intelligence is the meter.
The honest read on each
Gmail is still the default for good reason — free, extremely reliable, and its spam filtering remains the benchmark. Its ceiling is structural: one account at a time. Multi-sign-in is switching, not merging, so there’s no single stream, no rule layer spanning accounts, and no cross-account view of what’s waiting on you.
Superhuman sells speed and delivers it. Keyboard-first, deliberate shortcuts, a genuinely fast feel. It’s the most expensive entry point here with no free tier, so it’s a decision you make on workflow rather than price. If sub-100ms interaction is the thing you optimise for, nothing else on this list beats it.
Shortwave is the most AI-forward of the group, strong at search, built Gmail-first. Because usage is quota-based, heavy days mean watching the meter — fine if your usage is bursty, irritating if it’s constant.
Spark has the most generous real free tier: Smart Inbox and unlimited email accounts at $0, with paid tiers starting at $10. It’s the friendliest on-ramp. The trade-off is configurability — bucketing rather than rules you author yourself.
Missive isn’t competing for the same job. It’s a team tool: shared inboxes, comments on threads, assignments. For a team triaging one address together it’s excellent, and BYOK is the most cost-transparent AI arrangement on this list. For one person drowning in their own mail, the collaboration machinery is weight you don’t need.
Where MorningZero is actually different
Two things, both checkable.
Labeling isn’t metered. Every incoming message is classified, and that classification isn’t billed to your credits. That’s arithmetic rather than generosity: a small classification model costs a fraction of a cent per message, while the expensive work — reasoning over a long thread, writing a draft — only happens when you ask for it. Compare that with a model where the sorting draws on the same daily quota as everything else.
One login covers every account. Connect your mailboxes once and they merge into a single stream, tagged per message, with one rule layer and one “what needs my reply” across all of them, on every device you sign into.
And the measured part, from our own production database on 5 August 2026: after we fixed our Gmail push pipeline, the three notifications that came through the push path landed 6, 8 and 6 seconds after the mail did. Two that fell back to polling took 27 and 110 seconds.
Where MorningZero loses
Publishing the section above without this one would be marketing, not comparison.
- It’s Gmail and Workspace first. Microsoft accounts work but get less attention. If you’re Outlook-primary, something else probably fits you better today.
- It’s young. Superhuman and Spark have years of polish; Missive has a decade of team-workflow depth.
- Our real-time pipeline broke and we didn’t notice for 11 days. Between 23 July and 4 August 2026, Gmail push ingestion failed on every message — 686 failed events — because one deleted message stalled our history cursor. Mail kept arriving through the 2-minute polling fallback, so nothing looked broken while notifications ran up to two minutes behind Gmail’s own. It’s fixed, and there have since been 45 consecutive successful push ingests. No comparison table would have caught that, and it’s worth weighing when any young product tells you it’s real-time.
- No team collaboration. If you need shared inboxes and thread assignment, that’s Missive, and we’re not pretending otherwise.
Choosing without reading all of it
- Fastest keyboard-driven client, price not a factor → Superhuman
- AI-first Gmail and you’re fine with a daily AI quota → Shortwave
- Free, friendly, unlimited accounts on the free tier → Spark
- A team working one shared address → Missive
- One Google account, modest volume → stay on Gmail
- Several accounts in one stream, triage that isn’t metered, rules in plain English → MorningZero
Sources
All checked 5 August 2026:
- Shortwave pricing — plan prices, daily AI request ranges, per-search thread caps
- Spark pricing — free tier contents, Plus/Pro monthly and annual, meeting-note limits
- Missive pricing — per-user tiers, 20% annual discount, credits/BYOK
- Google Workspace pricing — which tiers include Gemini in Gmail
- MorningZero pricing — Free, Pro, Team
- Superhuman: pricing page (client-rendered), figures via usecarly and Morgen
Prices and quotas move. If you spot a stale number here, tell us and we’ll correct it with a fresh date.
Frequently asked
Which unified inbox has a genuinely free plan in August 2026?
Three of the six: Spark (Free, $0), Missive (free plan, no card required), and MorningZero (Free, $0). Superhuman and Shortwave are paid-only — Shortwave offers a 14-day trial. Gmail itself is free, but Gemini in Gmail needs a paid Workspace tier.
Does Shortwave limit how much AI you can use?
Yes, and it publishes the numbers. As of 5 August 2026 its Business plan ($30/seat/month) lists roughly 150–300 Standard-intelligence AI requests per day, a maximum of 50 threads per AI search, and 3 AI-powered filters. Premier ($45) doubles the usage allowance and Max ($120) is 6× Business.
What does MorningZero meter?
Only on-demand reasoning — Ask Zero chat, thread summaries, and draft generation. Background auto-labeling of incoming mail is not billed to your credits: it runs on a small, fast model whose per-message cost is low enough for MorningZero to absorb at any volume.
Is Superhuman's pricing published on its website?
Its pricing page renders client-side, so the figures can't be read from the raw page. Third-party trackers checked on 5 August 2026 list Starter at $30/user/month ($25 annual) and Business at $40 ($33 annual). Verify on Superhuman's own page before buying.