Spark vs Superhuman Mail

Updated October 2026 · AppBreakup editorial

Spark

Cross-platform email app from Readdle with a smart inbox, AI writing and shared team inboxes.

Free plan + paid

Visit Spark Spark profile

Superhuman Mail

A premium, keyboard-driven email client with AI features for Gmail and Outlook accounts.

Paid

Visit Superhuman Mail Superhuman Mail profile

The short answer

Pick Spark if you want a capable smart inbox for free, with support for any IMAP account and team features such as shared threads and private comments. Pick Superhuman if you live in Gmail or Outlook, want the fastest keyboard-driven workflow, and will pay for it. The biggest difference is price and reach: Spark has a free plan and wide account support, Superhuman is a premium tool for Google and Microsoft accounts.

Spark or Superhuman Mail: our take

Both are email clients that sit on top of your existing account and aim to make inbox work faster. Spark, from Readdle, sorts incoming mail into personal messages, notifications and newsletters, screens first-time senders with Gatekeeper, and supports snoozing, pinning, scheduled sending and follow-up reminders. Its AI assistant summarises threads and drafts replies, and teams can share threads, comment privately on emails and write messages together. Superhuman is built around keyboard shortcuts for people who live in their inbox, with a split inbox that separates mail from your team, VIPs and tools, plus reminders, scheduled sending, read status and AI that drafts replies, summarises threads and answers questions about your mail.

Pricing is very different. Spark's free plan covers individuals with unlimited email accounts; Plus costs $10 per user/month and Pro $20 per user/month, both on monthly billing, unlocking full AI features, meeting notes and admin controls. Superhuman has no free tier. After Grammarly acquired it in 2025, Mail is included in a Business plan at $33/member/month billed annually, alongside Grammarly, Docs and an AI assistant.

Account support and platforms also differ. Spark works with Gmail, Outlook, iCloud, Yahoo and any IMAP account, and has native apps for Mac, Windows, iOS and Android, but no web app. Superhuman works only with Gmail and Outlook accounts, ruling out iCloud or Fastmail, but runs on the web, Mac, Windows, iOS and Android. Spark syncs mail through Readdle's servers to deliver push and team features, which matters to some privacy-minded users.

For most people, and for small teams that want collaboration in the inbox, Spark offers a lot without paying. For professionals on Google or Microsoft accounts who handle a high volume of mail and value speed above cost, Superhuman can be worth it.

Choose Spark if…

People and small teams who want one smart inbox across all their devices
You want a free option (Superhuman Mail is paid only)
Free plan with unlimited accounts and a smart inbox
Shared threads, private comments and joint drafting for teams

Choose Superhuman Mail if…

Executives and heavy email users on Gmail or Outlook who value speed over price
You need Web, which Spark doesn't list
Very fast, keyboard-first workflow
Split inbox and reminders keep important threads visible

What is Spark?

Spark is an email client from Readdle that sorts incoming mail into personal messages, notifications and newsletters, and lets you snooze, pin, schedule and set follow-up reminders. Its Gatekeeper feature screens first-time senders, and the built-in AI assistant can summarise threads and draft replies. Teams can share threads, comment privately on emails and write messages together. It works with Gmail, Outlook, iCloud, Yahoo and any IMAP account. A free plan covers individuals with unlimited accounts and the core inbox features; paid Plus and Pro plans, billed per user, add the full AI features, meeting notes, larger team tools and admin controls. Spark runs on Mac, Windows, iPhone, iPad and Android. Because it syncs through Readdle's servers to provide push notifications and team features, people with strict privacy requirements may prefer a client that connects directly to the mail server. Some users also find that the newer AI-heavy layout adds clutter.

What is Superhuman Mail?

Superhuman Mail is a fast email client built around keyboard shortcuts, aimed at people who live in their inbox. It sits on top of Gmail and Microsoft 365 or Outlook accounts and adds a split inbox that separates mail from your team, VIPs and tools, plus snooze, reminders, scheduled sending, read status and AI that drafts replies, summarises threads and answers questions about your mail. The company was acquired by Grammarly in 2025, and the combined business now uses the Superhuman name for a suite that also includes Grammarly, Docs and an AI assistant; Mail is included in the Business plan rather than sold cheaply on its own. It has no free tier, so it costs considerably more than most clients. Apps cover the web, Mac, Windows, iOS and Android. It does not support generic IMAP accounts such as iCloud or Fastmail, which rules it out for many people outside Google and Microsoft.

Side by side

Attribute	Spark	Superhuman Mail
Pricing	Free plan + paid	Paid
Open source	No	No
Self-hostable	No	No
Platforms	macOS, Windows, iOS, Android	Web, macOS, Windows, iOS, Android
Best for	People and small teams who want one smart inbox across all their devices	Executives and heavy email users on Gmail or Outlook who value speed over price
Status	Active	Active