Comparison · Productivity
Inbox Zero vs Spark Mail: which AI agent is better?
A side-by-side look at Inbox Zero and Spark Mail on quality, price, capabilities and trust. Scores measure observable public data; prices come from each vendor's own pricing page. Every fact is sourced and dated.
| Inbox Zero Inbox Zero | Spark Mail | |
|---|---|---|
| Agent Score | 48 | 59 |
| Entry price | $20/mo | $10/mo |
| Trust | ✓ VERIFIED | ✓ VERIFIED |
| Capabilities documented | 5 | 5 |
| Free plan | No | No |
| Free trial | ✓ Yes | — |
| Public API | — | — |
| MCP support | — | — |
| Open source | ✓ Yes | — |
| Last verified | 13 Oct 2026 | 13 Oct 2026 |
Score breakdown
| Component | Inbox Zero | Spark Mail |
|---|---|---|
| Capabilities | 50 | 63 |
| Integrations | Not measured | Not measured |
| Documentation | Not measured | 70 |
| Pricing clarity | 100 | 100 |
| Transparency | 100 | 30 |
| Freshness | 100 | 100 |
| Human oversight | Not measured | 100 |
Choose Inbox Zero if…
- You want an open-source option.
Choose Spark Mail if…
- You want a higher Agent Score (59 vs 48).
- You want a lower entry price.
See the full picture: Inbox Zero · Spark Mail · more Productivity agents · all comparisons.