Inbox Zero vs Spark +AI
Inbox Zero
inbox-zero.aiSpark +AI
sparkmailapp.comSide by side
| Figure | Inbox Zero | Spark +AI |
|---|---|---|
| Price from | $20/mo | $10/mo |
| Free plan | — | Yes |
| Free trial | Yes | Yes |
| Open source | — | — |
| Web | Yes | — |
| Windows | — | Yes |
| macOS | — | Yes |
| iOS | Yes | Yes |
| Android | Yes | Yes |
| API | Yes | — |
| Self-hosted | Yes | — |
| Plans published | 4 | 4 |
| Spec score · AI Email Assistants | 8.4 (#8) | 8.6 (#7) |
| Email providers | It supports Gmail, Google Workspace, and Microsoft Outlook email accounts. | Spark supports Gmail, Google Workspace, Outlook, Office 365, Exchange Online, iCloud, Yahoo, and standard IMAP accounts. |
Plans
Inbox Zero
- Starter$20 a month
- Plus$35 a month
- Professional$50 a month
- EnterprisePriced on request
In their own words
Inbox Zero
Inbox Zero has no write-up on Specifiction yet; its figures are above.
Spark +AI
Spark +AI adds an AI assistant to Spark’s email app on Android, iOS, macOS, and Windows. It can search email, attachments, calendar items, and meeting notes, as well as draft or rephrase messages, proofread grammar and clarity, and translate. The assistant can check colleagues’ availability, schedule meetings, draft and send emails, and organize the inbox. It works with Gmail and Google Workspace, Outlook and Office 365 including Exchange Online, iCloud, Yahoo, and standard IMAP accounts; supported attachments are PDF and TXT. Spark lists integrations including Notion, Asana, Slack, Todoist, Zoom, Microsoft Teams, and HubSpot, with Salesforce and Pipedrive marked as coming soon. Spark says email and request history are processed locally, but a few query-related emails are sent to its AI provider; provider copies may be kept for up to 30 days for abuse monitoring. Spark says providers do not train models on user data, and AI can be disabled. Free includes five lifetime Meeting Notes; Plus costs $10 a month per user with 40 monthly notes, and Pro costs $20 a month per user with unlimited notes. AI features also use monthly quota.