SendGrid (Twilio) vs Knock
Legacy email infrastructure at scale — 100B+ emails/year
vs. Notifications-as-a-service: in-app feeds, email, push, SMS, chat via one API
Pricing tiers
SendGrid (Twilio)
Free Trial
100 emails/day for 60 days. After: upgrade required.
Free
Essentials — 50k
50,000 emails/month. 1 teammate. 2 event webhooks.
$20/mo
Essentials — 100k
100,000 emails/month.
$35/mo
Pro — 100k
100,000/mo. Dedicated IPs + subusers + email validation (2.5k). 1000 teammates. 5 webhooks.
$90/mo
Pro — 2.5M
2,500,000/mo. Same Pro features.
$449/mo
Premier (5M+)
Custom. SSO, custom overage rates, white-glove.
Custom
Knock
Developer
Free forever. 10K messages, 500 guide users, 500 AI credits/month.
$0 base (usage-based)
Starter
$250/mo. 50K messages, 2.5K guide users, 2K AI credits. Remove branding.
$250/mo
Enterprise
Custom pricing. White-label, i18n, data warehouse, Datadog, SCIM, SAML, HIPAA/BAA.
Custom
Free-tier quotas head-to-head
Comparing free-trial on SendGrid (Twilio) vs starter on Knock.
| Metric | SendGrid (Twilio) | Knock |
|---|---|---|
| guide users | — | 2500 users |
| guide users overage | — | $0.05/user USD/user |
| messages monthly | — | 50000 messages/mo |
| messages overage | — | $0.005/message USD/message |
Features
SendGrid (Twilio) · 12 features
- Dedicated IPs — Auto IP warmup, multiple IP pools per brand/customer.
- Dynamic Templates — Handlebars-based with versioning + A/B testing on subject/content.
- Email API (v3) — REST + SMTP. Dozens of endpoints for mail, stats, templates, subusers.
- Email Validation — Verify email addresses before sending. Credits per check.
- Event Webhook — Raw stream of send/delivery/bounce/open/click/unsubscribe/spamreport events.
- Inbound Parse — Route incoming mail → your webhook. Attachments + spam score.
- Link Branding — Track links on your own domain for reputation.
- Marketing Campaigns — Separate UI for bulk promotional sends. Segmentation, A/B, automation.
- SAML SSO — Premier tier only. SAML 2.0 auth for account access.
- Stats + Reports — Aggregated + per-category + per-subuser delivery metrics.
- Subusers — Isolate multi-tenant sends. Each subuser has own stats + API key + reputation.
- Suppression Groups — Granular unsubscribe groups (newsletter vs billing, etc.).
Knock · 13 features
- AI Agents — Autonomous notification drafting & workflow generation.
- Batch + Digest — Group notifications into digests on schedule or window.
- Chat — Slack, Microsoft Teams, Discord.
- Email — Send via SendGrid/Postmark/Resend/Mailgun/AWS SES as relays.
- Guides — In-product messaging, announcements, modals, banners.
- i18n / Localization — Translate templates by user locale.
- In-App Feed — Notification inbox with React/Vue/iOS/Android drop-in components.
- Multi-tenancy — Per-tenant branding, preferences, quiet hours.
- Outbound Webhooks — Subscribe to delivery events.
- Preferences — User + tenant preference center with granular controls.
- Push — iOS (APNs), Android (FCM), Expo, Web Push.
- SMS — Twilio, MessageBird, Telnyx, Vonage as providers.
- Workflows — Visual notification orchestration (branch, batch, delay, throttle).
Developer interfaces
| Kind | SendGrid (Twilio) | Knock |
|---|---|---|
| CLI | — | Knock CLI |
| SDK | sendgrid-go, sendgrid-java, @sendgrid/mail, sendgrid-php, sendgrid-python, sendgrid-ruby | knockapi (Python), knockapi (Ruby), knock-elixir, knock-go, knock-java, @knocklabs/node, @knocklabs/react |
| REST | SendGrid v3 API | Knock REST API |
| MCP | — | Knock MCP Server |
| OTHER | Event Webhook, Inbound Parse Webhook, SMTP Relay | Outbound Webhooks |
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