head to head · open source

Inbox Zero vs useSend

Inbox Zero has 12,238 GitHub stars, 1,536 forks, 209 open issues and last shipped yesterday. useSend has 4,686 stars, 421 forks, 37 open issues and last shipped 10 days ago. Inbox Zero leads on adoption by 161% (12,238 vs 4,686 stars). Inbox Zero is written in TypeScript under a custom or non-standard licence; useSend is written in TypeScript under AGPL-3.0. Inbox Zero has attracted 13% as many forks as stars, useSend 9%. Inbox Zero was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 2 topic tags (email, resend), so they are genuine substitutes rather than adjacent tools.

Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.

Inbox Zero ★ 12K useSend ★ 4.7K category Productivity & Utilities

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Side by side

Inbox Zero useSend
GitHub stars ★ 12K ★ 4.7K
License Custom / other AGPL-3.0
Written in TypeScript TypeScript
Last push 2026-09-17 2026-09-08
Forks ⑂ 1.5K ⑂ 421
Self-hosting Yes Yes
Data ownership Your server Your server

pick Inbox Zero if

  • You weight community size — 12K stars and counting
  • You want the Custom / other license terms
  • Your stack matches TypeScript
  • You value the larger contributor base for long-term maintenance

full Inbox Zero profile →

pick useSend if

  • You want the useSend feature set and don't need the biggest community
  • You prefer the AGPL-3.0 license terms
  • Your stack matches TypeScript
  • You evaluated both and useSend fits your workflow better

full useSend profile →

About Inbox Zero

Inbox Zero is an open source AI email assistant written in TypeScript and placed in the email productivity ecosystem. It is a web application built with Next.js, shadcn/ui, Prisma, and related tools. The project describes itself as a 24/7 assistant that organizes email, drafts replies, manages calendar context, and handles attachments.

read the full Inbox Zero overview →

About useSend

useSend is open source sending infrastructure, positioned directly as an alternative to Resend, Sendgrid and Postmark, and written in TypeScript under the AGPL 3.0 license. It lives in the email and communication ecosystem, filed under Productivity & Utilities / Email & Communication. Like most email products on the market, it uses Amazon SES under the hood to transmit messages, and it wraps that delivery layer in an open dashboard for sending reliably and cheaply. The project's stated premise is simple: pay per email sent, rather than paying for contact storage. The repository carries 4676 stars, 421 forks and 3…

read the full useSend overview →

More in Productivity & Utilities

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More Email & Communication projects

Compare either of these against the rest of the Email & Communication field.

Inbox Zero vs Ntfy Inbox Zero vs Plunk Inbox Zero vs Freescout Inbox Zero vs Keila Inbox Zero vs Sendportal Inbox Zero vs UnInbox Inbox Zero vs DoubleZero Inbox Zero vs Sessy Inbox Zero vs Hyvor Relay Inbox Zero vs Twake Mail Inbox Zero vs AgentMail

Frequently asked questions

Is Inbox Zero or useSend more popular?

Inbox Zero has 12,238 GitHub stars and useSend has 4,686. Inbox Zero has the larger community by that measure.

Are Inbox Zero and useSend free?

Both are open source. Inbox Zero has no licence declared in this registry, and useSend is licensed under AGPL-3.0. Both are free to self-host.

What is the difference between Inbox Zero and useSend?

Inbox Zero is written in TypeScript and useSend in TypeScript. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.

Which should I choose, Inbox Zero or useSend?

Choose Inbox Zero if you want the larger community (12,238 stars) or its Custom / other licence terms. Choose useSend if its feature set, stack or AGPL-3.0 licence fits better. Both are self-hostable.