Courier vs Twilio: Why the Best Setup Uses Both

Short answer

Courier runs on top of Twilio, not instead of it. Twilio delivers the messages; Courier decides what to send, designs how it looks, and routes it across channels.

Courier natively supports the whole Twilio messaging stack (Twilio SMS, SendGrid, Segment, and WhatsApp), then adds the layer you'd otherwise build yourself:

• Journeys for multi-step, multi-channel workflows
• Design Studio to create and manage beautiful emails without code
• Preferences plus a drop-in in-app Inbox

Most teams use both together. The only Twilio products outside this are voice and video, which are calling APIs, not messaging.

The Twilio messaging stack, supported by Courier

Everything Twilio offers on the messaging side is a first-class integration in Courier:

Courier also adds channels Twilio has no equivalent for: push, an embeddable in-app Inbox, and native Slack and Microsoft Teams delivery. You connect Twilio for the channels it serves, and Courier covers the rest of your messaging from the same place.

Two layers of one stack

Courier and Twilio operate at different layers, which is why they fit together rather than compete.

Twilio is the delivery engine. It sends the SMS, delivers the email through SendGrid, and captures the event through Segment, reliably and at scale. What it doesn't do is decide which message goes out, design how it looks, coordinate channels, or respect a user's preferences. On Twilio alone, that layer is yours to build and maintain. Courier is that layer.

Journeys: multi-step, multi-channel orchestration

Journeys is Courier's visual workflow builder and the heart of the orchestration layer. A journey starts from a Segment event, an API call, or a user attribute, then runs whatever sequence you design across every channel you've connected.

Inside a journey you can:

• Send across channels in steps. Email through SendGrid, SMS through Twilio, then WhatsApp, push, Slack, Microsoft Teams, or the in-app Inbox, in whatever order the logic calls for.
• Branch on behavior and traits. Route on Segment traits like plan or region, or on engagement like whether an email was opened.
• Control timing. Add delays, schedules, quiet hours, and time zones so messages arrive when they should.
• Reduce fatigue. Batch events into digests and throttle sends.
• Add intelligence. Run an AI step to score a user or generate personalized content, then branch on the result.
• Apply preferences automatically. Every send checks the user's channel preferences before it goes out.

The result is the multi-step, multi-channel logic you'd normally hand-build around Twilio, expressed once in a visual builder. Product and growth teams can change a flow without a deploy, and no one maintains queues, retries, or fallback code by hand.

Design Studio: create and manage beautiful emails

Design Studio is Courier's visual editor for message content, and it's where email lives. You design branded, responsive emails without code, preview them next to your SMS, push, and in-app versions on one canvas, and manage every template in one place. Changes ship in minutes, with no deploy and no engineering ticket.

The dovetail with Twilio is direct: the emails you build in Design Studio are delivered through your SendGrid account. Content and design stay in Courier, where anyone on the team can update them, while delivery stays on Twilio's infrastructure. The same editor covers the content for every other channel in the journey, so a campaign's email, SMS, and in-app messages are designed and versioned together instead of scattered across tools and code.

Preferences, Inbox, and one place to watch it all

Two more parts of the layer round out what Courier adds on top of Twilio:

• Preferences. A built-in preference center, with a drop-in UI component, lets users control which channels and message types they receive. Journeys enforce those choices on every send, so you don't build opt-out logic yourself.
• In-app Inbox. A drop-in notification center with real-time sync and SDKs for React, JavaScript, iOS, Android, React Native, and Flutter, plus Toasts. It's a channel Twilio doesn't offer, delivered from the same journey as your email and SMS.

Underneath all of it, Courier keeps one message log across every provider, so you track email, SMS, WhatsApp, push, and in-app delivery, engagement, and provider responses in a single place instead of stitching dashboards together.

Putting it together

Here's how the features and the Twilio stack combine in a single onboarding journey.

A Segment event starts the journey. Courier connects to Segment as a destination, so no webhook listener or glue code is needed:

analytics.track("trial_started", {
  userId: "1234",
  plan_type: "pro",
  email: "jane@example.com"
});

From there, one journey handles the rest:

• A welcome email, designed in Design Studio and personalized with the Segment traits, goes out through SendGrid.
• After a two-hour delay, if the email is unopened, Courier sends an SMS through Twilio.
• If the user is active in the app, Courier skips the SMS and shows an in-app message in the Inbox instead.
• Any channel the user has opted out of is skipped automatically.

You can also trigger the same orchestration from the API, fanning out across providers in one request:

{
  "message": {
    "to": {
      "email": "jane@example.com",
      "phone_number": "+14155550123"
    },
    "template": "onboarding-welcome",
    "routing": {
      "method": "all",
      "channels": ["email", "sms"]
    },
    "providers": {
      "email": "sendgrid",
      "sms": "twilio"
    }
  }
}

This is also how Twilio's own teams use Courier internally; Twilio is a Courier customer and investor.

Pricing

The models differ, so a direct per-unit comparison is misleading. Twilio is pay-as-you-go at the delivery layer, with US SMS starting around $0.0083 per message (carrier surcharges and phone number rental are billed on top) and email billed through SendGrid. Courier is free for the first 10,000 messages a month, then bills usage-based at $0.005 per message on the Business tier, on top of the underlying provider cost. Because Courier orchestrates rather than delivers, you pay Twilio for delivery and Courier for the layer above it. Provider rates change often, so check current pricing before you model costs.

When you still go to Twilio directly

You use Twilio's APIs directly for the products that aren't messaging orchestration: programmable voice and video. If you're building calling features, video rooms, or fully custom communication infrastructure, that's Twilio's domain and Courier doesn't sit in front of it. For everything on the messaging side (SMS, email, WhatsApp, and the data that triggers it), Courier and Twilio are designed to run together.

Frequently asked questions

Does Courier support the full Twilio stack?

On the messaging side, yes. Courier natively supports Twilio SMS, SendGrid for email, Segment for events, and WhatsApp, and orchestrates them together through Journeys, with channels Twilio doesn't offer like Slack, Microsoft Teams, push, and in-app. Twilio's voice and video are calling APIs you'd use directly.

What is the difference between Courier and Twilio?

They operate at different layers. Twilio is a provider that delivers messages directly. Courier is the orchestration and content layer on top: Journeys builds the multi-step, multi-channel workflow, Design Studio creates the content, and Courier applies preferences, usually sending the underlying SMS and email through Twilio and SendGrid.

Do I have to replace Twilio to use Courier?

No. Courier runs on top of Twilio. You keep your Twilio SMS, SendGrid, and Segment accounts and connect them to Courier, which adds Journeys, Design Studio, preferences, and cross-channel routing without changing how messages are delivered.

Can I design and manage emails in Courier?

Yes. Design Studio is a visual editor for building branded, responsive emails without code, previewing them alongside your other channels, and managing all your templates in one place. Those emails are delivered through your SendGrid account, and you can update them without a deploy.

Does Courier support WhatsApp?

Yes. WhatsApp is a supported channel in Courier, and Twilio is one of the providers that can deliver it, so you can include WhatsApp in the same journey as email, SMS, and in-app.

Is Courier cheaper than Twilio?

The pricing models differ, so neither is cleanly cheaper. Twilio bills per message or minute at the delivery layer. Courier bills $0.005 per message for orchestration after a 10,000-message monthly free tier, on top of the provider cost. Running Twilio through Courier means you pay both, in exchange for not building the orchestration and content layer yourself.

Who should use Twilio on its own?

Teams that only need raw communication primitives, especially voice or video, or teams that want to own their routing, content, and preference logic end to end, can use Twilio directly without Courier.