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A practical comparison for product teams. Have a side-by-side look at setup effort, pricing flexibility, deliverability model, and developer experience when sending transactional and product emails.
Keplars is built for developers who want to move quickly without setup friction. Connect via OAuth, API, SMTP, or webhooks and start sending in minutes, with clean defaults, clear logs, and predictable behavior that feels natural in real production workflows.
Keplars is designed for product emails that must reach the inbox. By separating transactional traffic from marketing flows and enforcing clean sending behavior, Keplars achieves 99.99% inbox placement with an average spam rate of ~0.01%.
Instead of forcing teams into rigid tiers, Keplars uses dynamic, component-based pricing. You pay for what you actually use, whether that's more emails, domains, webhooks, or team members.
| Category | Keplars | SendGrid |
|---|---|---|
| Setup Time | Minutes | Several days (sometimes weeks) |
| UX | Simple, developer-first | Complex and extensive |
| Getting Started | OAuth login with Gmail / Workspace / Outlook | Domain + sender configuration required |
| OAuth Emails | Yes (send via connected inbox instantly) | Not supported |
| Custom Domain Support | Optional, when ready | Required for production |
| SPF / DKIM / DMARC | Auto-managed or custom | Manual setup |
| API First | REST APIs | REST APIs |
| SMTP Relay | Yes | Yes |
| Webhooks | Event-based | Event-based |
| AI-generated Email Templates | Yes | No |
| No-Code Email Builder | Yes | No |
| Data Retention | Configurable, short by default | Limited (often ~3 days on lower tiers) |
| Pricing Model | Fully dynamic, usage-based | Volume-based tiers |
| Free Plan | Always-free (no credit card) | Trial only |
| MVP Friendly | Designed for early-stage usage | Often heavy early |
| Inbox Placement Control | Strong isolation of transactional flows | Shared reputation unless isolated |
| Spam Risk | Very low due to isolated product-email traffic | Higher if traffic mixes |
| Delivery Reliability | Predictable, production-oriented delivery | Configuration-dependent |
| Learning Curve | Low | Medium to high |
Disclaimer: Comparisons are provided for informational purposes only and are based on publicly available data at the time of publication.