Auth0 vs Resend
Customer identity platform from Okta
vs. The email API for developers — built by the Nodemailer team
Pricing tiers
Auth0
B2C Essentials
Starting at 500 MAUs. Pro MFA, RBAC, passwordless, SAML, 10 orgs.
$35/mo
B2B Essentials
Unlimited orgs, 3 SSO connections, RBAC.
$150/mo
B2C Professional
Starting at 500 MAUs. Includes attack protection, custom DB, enterprise MFA.
$240/mo
B2B Professional
5+ SSO connections, attack protection, custom DB.
$800/mo
Enterprise
Custom. 99.99% SLA, dedicated support.
Custom
Resend
Free
3,000 emails/month, 100 emails/day. 1 custom domain. Ideal for side projects.
Free
Pro — 50k
50,000 emails/month. 10 custom domains. Priority support.
$20/mo
Pro — 100k
100,000 emails/month. 10 custom domains.
$35/mo
Scale — 100k+
Tiered from 100k → 2.5M emails/month. Dedicated IP add-on available.
$90/mo
Scale — 2.5M
2.5M emails/month.
$1150/mo
Enterprise
3M+/month, dedicated IP included, SSO, custom contract.
Custom
Free-tier quotas head-to-head
Comparing b2c-essentials on Auth0 vs free on Resend.
| Metric | Auth0 | Resend |
|---|---|---|
| custom domains | — | 1 domains |
| emails per day | — | 100 emails/day |
| emails per month | — | 3000 emails/month |
| mau start | 500 MAU | — |
| sso connections | 0 conns | — |
Features
Auth0 · 14 features
- Attack Protection — Bot detection, brute-force protection, breached-password detection, suspicious I…
- Auth0 Actions — Node.js + TS hooks that run during auth flows (login, post-login, signup, MFA). …
- Auth0 FGA (OpenFGA) — Fine-grained relationship-based authorization (ReBAC). Based on Google Zanzibar.
- Custom Database — BYO user DB: scripts in Actions read from your database and create Auth0 users o…
- Custom Domain — Serve auth at auth.yourbrand.com with managed cert.
- Enterprise SSO — SAML 2.0 + OIDC + AD/LDAP enterprise connections. Per-tenant or per-org.
- Log Streaming — Stream tenant logs to Datadog, Splunk, Sumo Logic, Azure Sentinel, HTTP, Mixpane…
- Machine-to-Machine — Client-credentials grant for backend services.
- Multi-Factor Auth — SMS, Voice, Email, TOTP, WebAuthn (biometrics), Push (Guardian app), Duo.
- Organizations — Multi-tenant B2B: orgs with invitations, roles, branding, enterprise connections…
- Passkeys — FIDO2/WebAuthn passkey sign-in.
- Passwordless — Email magic link + code, SMS code, WebAuthn.
- RBAC — Roles, permissions, API scopes — attach to users or orgs.
- Universal Login — Hosted login page with customization, multi-factor flows, passwordless, social, …
Resend · 12 features
- Audiences — Contact list management with custom fields.
- Batch Send — Send up to 100 emails in one API call.
- Broadcasts — Bulk email campaigns with audiences, A/B testing, analytics.
- Dedicated IP — Add-on for high-volume senders. Auto warmup.
- Domains — DKIM/SPF/DMARC auto-verification. Per-domain analytics.
- Idempotency — Prevent duplicate sends with Idempotency-Key header.
- Logs + Analytics — Full email logs, delivery heatmap, events table.
- React Email — OSS library (3M+ downloads) to compose emails in React/JSX.
- Scheduled Send — scheduledAt parameter for future delivery.
- Send API — POST /emails endpoint to send. Supports attachments, scheduled send, idempotency…
- Suppressions — Auto-managed bounce + complaint list. API to add/remove.
- Webhooks — Email lifecycle events: sent, delivered, bounced, complained, opened, clicked.
Developer interfaces
| Kind | Auth0 | Resend |
|---|---|---|
| CLI | Auth0 CLI | Resend CLI |
| SDK | Auth0 Android, Auth0 iOS/Swift, @auth0/nextjs-auth0, Auth0 React SDK, Auth0 SPA.js SDK, Go Auth0 SDK, Node Auth0 Backend SDK, Python Auth0 SDK | react-email, resend-go, resend-node, resend-php, resend-python, resend-ruby |
| REST | Authentication API, Management API | Resend REST API |
| OTHER | — | SMTP Relay, Webhooks (Svix) |
Staxly is an independent catalog of developer platforms. Outbound links to Auth0 and Resend are plain references to their official websites. Pricing is verified against vendor pages at publication time — reconfirm before buying.
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