The Best Resend Alternative for Transactional Emails
Compare Keplars and Resend across APIs, SMTP, templates, analytics, automations and email infrastructure. Built for startups, SaaS products and growing teams.
Why Teams Look For a Resend Alternative
Resend has become popular among developers due to its modern API experience and React Email support. As applications grow, many teams begin looking for additional capabilities such as email automations, OAuth sending, AI templates, and a broader email infrastructure that handles both product and marketing emails.
- OAuth Email Sending
Resend routes all email through its own servers. Keplars lets you authenticate through Gmail, Google Workspace, or Microsoft Outlook via OAuth and send from your real inbox reputation.
- More Than an API
Resend focuses on transactional delivery. Keplars includes automations, AI-generated templates, a unified drag and code editor, marketing email campaigns, and a full analytics dashboard as part of the same platform.
- Better Economics
Keplars includes 5,000 free emails per month versus 3,000 with Resend. Paid plans start at $5/mo versus $20/mo. You get more of the platform for significantly less.
Resend vs Keplars Feature Comparison
A side-by-side look at features, infrastructure, developer tools, and pricing.
| Feature | Keplars | Resend |
|---|---|---|
| Email API | REST API with simple HTTP calls | REST API |
| SMTP | Port 587, STARTTLS, drop-in replacement | Available |
| OAuth Email Sending | Gmail, Google Workspace, Outlook | Not supported |
| No DNS Setup Required | Start sending via OAuth in minutes | DNS records required for all custom domains |
| Developer SDKs | 11 languages | 10 languages |
| CLI | Full developer CLI | Not available |
| Unified Email Editor | Drag & drop + code editor in one tool | React Email and visual designer are separate tools |
| Canva / Figma Import | Import designs and send directly | Not supported |
| Real-time Email Tracking | Open time, delivered time, click time per email | Basic open and click events |
| Webhooks | All lifecycle events, included | Event-based |
| Automations | Included with AI-generated templates | Basic triggers only, not a focus |
| Marketing Campaigns | Campaigns and lifecycle flows, included | Broadcasts only, no campaign management |
| Scheduling Emails | Included | Available |
| Mailbox Warmup | Included | Not available |
| Built-in Spam Prevention | Zero-tolerance spam policy enforced | Basic abuse detection, not product-first |
| Sandbox Mode | Full sandbox. No impact on daily limit | Test mode counts against daily sending limit |
| Analytics | Real-time dashboard, all plans | Available, limited depth |
| Domain Authentication | Auto-managed SPF, DKIM, DMARC | Manual DNS setup required |
| Integrations | Vercel, Firebase, Supabase, Lovable, n8n, Zapier, Bubble, Payload CMS, PocketBase, React Email, and more | Next.js, Remix, Nuxt, Segment, framework-focused |
| Dynamic / Usage-aware Pricing | Pay for what you use, from $5/mo | Fixed tiers from $20/mo |
| Marketing Email Pricing | Usage-based. Pay per email sent, not contacts stored | Contact-based. From $40/mo per 5k contacts, regardless of emails sent |
| Free Plan | 5,000 emails/mo | 3,000 emails/mo |
| Support | Responsive, all plans | Community and docs-first |
Why Developers Choose Keplars Over Resend
- OAuth Email Sending
Send from Gmail, Google Workspace, or Outlook. Your real inbox reputation powers every email.
- AI-Generated Templates
Generate polished, responsive email templates with AI. No designer required.
- CLI for Developers
Manage sending, templates, and domains directly from the terminal without touching the dashboard.
- Canva and Figma Import
Import designs from Canva or Figma into the Keplars editor and send them as emails directly.
- Unified Email Editor
The Keplars editor combines drag-and-drop and raw code editing in one tool. Switch between visual and code mode without losing work.
- Mailbox Warmup
Automatically warm up new sending domains and mailboxes to build reputation before sending at scale.
- Wider Integration Ecosystem
Integrates natively with Vercel, Firebase, Supabase, Lovable, n8n, Zapier, Bubble, Payload CMS, PocketBase, React Email, and Dodo Payments.
- Better Free Tier
5,000 emails per month on the free plan versus Resend's 3,000. More room to build and test before you ever pay.
Built for Modern SaaS Applications
Every email type your product needs, handled from one platform.
Welcome emails and account setup sequences delivered reliably from day one.
Secure, branded password reset links delivered instantly to your users.
One-time password codes that arrive in under 5 seconds, every time.
Email address confirmation flows that complete fast and land in the inbox.
Passwordless login links sent and received in seconds for frictionless auth.
Invoices and receipts as HTML or PDF delivered straight to customer inboxes.
Trial expiry, renewal reminders, and subscription change confirmations.
Onboarding sequences, re-engagement flows, and product update announcements.
Email Infrastructure Beyond Transactional Emails
Resend is primarily an email delivery API. Keplars is a complete email platform. Manage everything from a single dashboard.
- Transactional Emails
APIs and SMTP for OTPs, resets, invoices, and all product-critical email.
- Marketing Emails
Broadcast campaigns and lifecycle email flows from the same platform.
- Templates
AI-generated, drag-and-drop, and code editor. All in one unified interface.
- Automations
Trigger-based email workflows with branching logic and delay controls.
- Real-Time Tracking
Open time, delivered time, click time, and full event timelines per email.
- Domains and Analytics
Manage sending domains, SPF, DKIM, DMARC, and a live analytics dashboard in one place.
How to Migrate From Resend to Keplars
The SDK signatures are nearly identical. Most migrations take under 30 minutes.
Sign up at dash.keplars.com and create a new project. Takes under a minute.
Add your sending domain in the Keplars dashboard. SPF, DKIM, and DMARC are configured automatically.
Replace the Resend client with the Keplars SDK. The method signature is nearly identical.
Copy your existing HTML templates or rebuild them with the AI-powered Keplars editor.
Use the real-time Keplars dashboard to track opens, clicks, bounces, and delivery times.
Before vs After
import { Resend } from 'resend';
const resend = new Resend(process.env.RESEND_API_KEY);
await resend.emails.send({
from: '[email protected]',
to: '[email protected]',
subject: 'Welcome!',
html: '<h1>Welcome aboard</h1>',
});import { Keplars } from '@keplars/sdk';
const keplars = new Keplars({
apiKey: process.env.KEPLARS_API_KEY,
});
await keplars.emails.sendInstant({
to: ['[email protected]'],
subject: 'Welcome!',
html: '<h1>Welcome aboard</h1>',
is_html: true,
});Webhook event names
Keplars and Resend use the same event naming convention. Your webhook handlers work without any changes.
Templates, contact lists, and domain settings all carry over. Full details in the migration guide.
Why Startups Choose Keplars
- Scalable Infrastructure
Built to grow with your product. Start free, scale to millions of emails without re-architecting your email stack.
- Developer Experience First
Clean REST APIs, clear documentation, a developer CLI, and predictable behavior that feels natural in real production workflows.
- Transactional and Marketing Together
Stop running separate tools for product emails and marketing campaigns. Keplars handles both from a single dashboard.
- Analytics That Actually Help
Real-time open rates, click rates, delivery timelines, and bounce tracking. Know what happened to every email you sent.
- Automations Without Extra Cost
Trigger-based email workflows, drip sequences, and re-engagement flows are included. No additional tool or tier required.
- One Platform for Everything
APIs, SMTP, webhooks, templates, automations, tracking, domains, and analytics in one place. No tool sprawl.
Frequently Asked Questions
Ready to switch from Resend?
Disclaimer: Comparisons are provided for informational purposes only and are based on publicly available data at the time of publication.
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