Short answer: Inbox Zero and Jace do much of the same job. Both connect to Gmail or Outlook, sort new mail and leave reply drafts in your voice waiting in your inbox. Inbox Zero is open source, can be self-hosted and comes with a free email app. Its AI plans start at $25 a month, less 20% on yearly billing. It adds bulk unsubscribe, a cold-email blocker and a meeting notetaker on Plus. Jace costs $25 a month or $20 billed yearly. It drafts from the full thread and its attachments, and prepares follow-up drafts on threads waiting for a reply. Its Flows connect email to tools such as HubSpot and Slack. Pick Inbox Zero if open source, self-hosting or a free app matters to you. Pick Jace if you want attachment-aware drafts and plain-English workflows across your tools.
We make Jace. Inbox Zero facts come from its homepage and pricing page, opened on 9 November 2026. We have not run timed tests on either product.
Inbox Zero vs Jace at a glance
| Inbox Zero | Jace | |
|---|---|---|
| Providers | Gmail, Google Workspace and Outlook | Gmail and Outlook (Microsoft 365 and Outlook.com) |
| Where you work | Inside Gmail or Outlook, or the Inbox Zero email app. Also from Slack, Telegram or Teams | Inside Gmail or Outlook, plus the Jace web app |
| Sorting | Automatic categories such as To Reply, Newsletter and Cold Email, or your own | AI labels such as Needs Reply, Waiting and FYI, or your own described in plain English |
| Reply drafts | Drafts in your voice for every email needing a reply, using email history and calendar | Drafts for the labels you choose, using the full thread, attachments, calendar, rules and writing style |
| Follow-ups | Not described on the pages we checked | Waiting label, with a follow-up draft after 3 days without a reply |
| Automations | Rules written in plain English | Flows written in plain English, with steps in connected tools |
| Clean-up | Bulk unsubscribe, bulk archive, cold-email blocker | Low-priority mail labelled, such as Promotion |
| Open source | Yes, and can be self-hosted | No |
| Mobile | Native iPhone app. Android app listed as due for an update | No native app yet. Drafts and labels show in your phone's Gmail or Outlook app |
| Security | States SOC 2 Type 2 certification | See Jace security |
| Price | Starter $25, Plus $35, Professional $50 a month, save 20% yearly. Free email app. 7-day trial | Plus $25 a month or $20 billed yearly. Pro $50 or $40. 7-day trial |
Inbox Zero prices from getinboxzero.com/pricing on 9 November 2026. Jace prices from jace.ai/pricing.
What Inbox Zero does well
Inbox Zero is one of the few AI email assistants with open-source code. Its homepage says the assistant, web app and desktop email app are on GitHub, and that you can self-host for full control. For teams with strict data rules, self-hosting is a real advantage.
It also covers clean-up well. Bulk unsubscribe and bulk archive show the senders you never read and clear them in a click. A cold-email blocker keeps pitches out. Email analytics show who sends you the most. The free email app puts every Gmail and Outlook account in one inbox on the web, on desktop and on iPhone. The Plus plan adds an AI meeting notetaker, a Slack integration, app integrations and auto-filing of attachments.
When to pick Inbox Zero instead
- Open source or self-hosting matters. You want to read the code or run it on your own servers.
- You want a free email app with AI added only if you need it.
- Bulk unsubscribe and cold-email blocking are the main jobs.
- You need a SOC 2 Type 2 report today. Inbox Zero states that certification. Jace's security page says it follows SOC 2 controls, which is not the same as a certification report.
- You manage email from chat apps. Inbox Zero lets you work from Slack, Telegram or Teams.
When Jace is the better Inbox Zero alternative
- Your replies depend on attachments. Jace reads the PDFs, Word files and spreadsheets in a thread before it drafts. A reply about a contract or invoice can then use what is in the file (how Jace reads attachments).
- Follow-ups should come with a draft. When a thread you sent sits in Waiting for 3 days, Jace writes the nudge for you to review.
- Email turns into work in other tools. A Flow is written in plain English. For example: "when a client sends a signed proposal, draft a kickoff reply with open times and create the deal in HubSpot" (Flows). Slack, Google Drive and OneDrive are built in, and tools such as Notion connect through MCP (Integrations).
- You want to ask your inbox questions. Jace's chat searches your connected history: 1 year on Plus, 3 years on Pro.
- Sending stays with you, with an opt-in. Drafts land in your Drafts folder. You can switch on auto-send for one label or Flow, after a warning.
Jace's limits, plainly: no open source or self-hosting, no free plan, no native mobile app yet, and no bulk unsubscribe tool.
Price for one person
Inbox Zero Starter is $25 a month, or 20% less on yearly billing. Plus, with integrations and the notetaker, is $35. Jace Plus is $25 a month or $20 billed yearly, with 2 inboxes and AI drafting included. Jace Pro is $50 or $40 billed yearly, with 8 inboxes and custom integrations (pricing). Both offer a 7-day trial.
FAQ
What is a good Inbox Zero alternative? Jace, Fyxer and Superhuman's Email Assistant all draft replies inside Gmail or Outlook. Jace fits if you want attachment-aware drafts and Flows across your tools. See the best AI email assistants in 2026.
How much does Inbox Zero cost? On 9 November 2026 Inbox Zero listed Starter at $25, Plus at $35 and Professional at $50 a month, with up to 20% off on yearly billing. Its email app is free, and the AI plans have a 7-day trial.
Is Inbox Zero open source? Yes. Inbox Zero says its AI assistant, web app and desktop email app are open source on GitHub, and that it can be self-hosted. Jace is not open source.
Does Jace work with Gmail and Outlook like Inbox Zero? Yes. Jace works with Gmail and Google Workspace, and with Outlook on Microsoft 365 and Outlook.com (Jace for Gmail, Jace for Outlook).
Does Jace send emails without my approval? Not by default. Drafts land in your normal Drafts folder. Auto-send stays off unless you turn it on for a specific label or Flow, and Jace warns you first.
Try Jace on your own inbox
Connect Gmail or Outlook and compare Jace's drafts with Inbox Zero's on the same threads for 7 days. Start your free Jace trial, or compare plans first. Jace is used by lawyers and consultants who answer their own client email.
Also comparing: Fyxer, Superhuman Email Assistant, SaneBox, Spark and Mailbutler.
