Knock vs. Loops
Unlock customer engagement that runs itself
Modern teams choose Knock to launch messaging flows with a prompt. Set your goals, and Knock agents identify, build, and ship the customer journeys to hit them.
Top reasons teams choose Knock over Loops
Learn why companies reach for Knock when looking for Loops alternatives.
Agentic customer engagement
Knock is built for agents to do the work. Build complex customer journeys with a prompt, generate on-brand templates, and manage all your messaging from Claude, Slack, or the terminal.
One system for all messaging
Manage your product, marketing, and transactional messaging from one place. Send messages across email, in-app, SMS, push, and chat, triggered from API calls, events, or audience changes.
Native in-app messaging
Show in-app banners, modals, and cards that use your own UI components. Guides share audiences and analytics with broadcasts and workflows, so in-app nudges can be coordinated with other messaging in one system.
Advanced sending controls
Apply batching, digests, throttling, and idempotency to lifecycle messaging and product notifications. Send timely messaging without fear of notification overload. No custom logic needed.
Infrastructure-grade reliability
Knock's messaging infrastructure powers billions of notifications in production for world-class organizations like Vercel, Webflow, and Zapier, with 99.99% uptime, git-style versioning, and full observability.
Usage-based pricing
Connect providers you already use, such as Amazon SES and Twilio, and only pay for the messages you send. Every plan gives you unlimited contacts, team members, workflows, and channels on every plan, with no hidden costs.
Ship coordinated, cross-channel messaging
Coordinate in-app and out-of-app flows that reach the right users at the right moments. Send dynamic, on-brand messages across email, in-app, push, SMS, and chat.
The New user onboarding workflow in the builder, at Collab.io. An agent step is dragged in from Add a step under the new-user-signup trigger and its prompt is typed: Claude Sonnet 5 writes a welcome line for the recipient that fits their role, into a welcome_line response property. The welcome email greets the recipient by first name, then uses that line. After a 3 day delay, a branch on Created a project? sends a Day 3 tips email to people who have not created one yet and an in-app feed message to everyone else.
Trigger smart automations that send messages across any channel.
email / in-app / push / SMS / chat
Unify product, CDP, and warehouse data
Sync data and events from your product, CDP, warehouse, and connected tools to build dynamic audiences and trigger messaging based on any attribute or signal.
Product usage from the Knock SDKs, traits from a CDP such as PostHog, Segment, or Amplitude, account data synced by Hightouch from a warehouse such as Snowflake, Databricks, or BigQuery, and billing data from Stripe flow into one user model in Knock as user properties.
A dynamic audience updates as those properties change, and a user entering the audience triggers a workflow.
Knock vs. Loops feature comparison
| Feature | Knock | Loops |
|---|---|---|
| Lifecycle and marketing | ||
| One-time and recurring broadcasts to audiences | Yes (broadcasts, sent from the dashboard) | Yes (campaigns) |
| Dynamic audiences built from user properties and events | Yes, reusable across workflows, broadcasts, and guides | Yes (audience filters) |
| Multi-step lifecycle journeys (onboarding, activation, win-back) | Yes (workflows with branching, delays, and AI agent steps) | Yes (loops) |
| Workflow and broadcast analytics | Yes | Yes |
| Goals with conversion attribution | Yes | Email engagement metrics |
| In-app messages, banners, and nudges in your own components | Yes (guides) | No |
| Drag-and-drop email editor for non-technical users | Yes | Yes |
| Self-serve copy and targeting edits without a deploy | Yes | Yes |
| One system for every message | ||
| Product, lifecycle, and transactional messaging in one platform | Yes | Marketing and transactional email |
| Email, SMS, push, in-app, Slack, Microsoft Teams, and WhatsApp | Yes, native | |
| Bring your own providers (25+, such as Amazon SES and Twilio) | Yes | Loops sending |
| Batching, digests, throttling, and idempotency | Yes, built in | No |
| Cross-channel user preference center | Yes | Email mailing list preferences |
| Multi-tenancy | Yes | No |
| Reliability and control | ||
| Delivery logs with downstream provider responses | Yes | Email sending metrics |
| Git-style versioning and multiple environments | Yes | No |
| CLI, Management API, and MCP server | Yes | REST API |
| 99.99% uptime | Yes | Contact Loops for SLA details |
Frequently asked questions
Knock is developer-first messaging infrastructure that provides APIs and SDKs for engineering teams to build custom notification systems across multiple channels. Loops is an email platform designed for SaaS companies to manage marketing and transactional emails.
Knock supports product, growth, and engineering-owned messaging driven by events across email, SMS, push, in-app, and chat channels, while Loops focuses primarily on email campaigns and transactional emails.
While Loops can send transactional emails, it's not as flexible as a notification system you'd build yourself. Developers often find Loops's email-only approach limiting for complex notification logic, whereas Knock provides granular, programmatic control through APIs and event-driven workflows designed specifically for transactional product and customer messaging across multiple channels.
Yes, Knock supports both transactional and marketing messaging. Features like Broadcasts and Guides allow engineering, product, and growth teams to work collaboratively in Knock to send relevant lifecycle messaging and one-off promotional emails, just like Loops.
Non-technical users can easily create messaging workflows, manage notification templates, edit and send one-time messages, and view analytics without any developer involvement.
Loops offers email campaign analytics and performance tracking. Knock also provides detailed engagement analytics across channels, plus end-to-end observability for delivery tracking, message debugging, and API logs that give you complete visibility into your messaging infrastructure. Knock can also sync message event data directly to your data warehouse.
Knock starts with a one-time technical integration. In return, your team gets more control and flexibility, with features like infrastructure as code, version control, and programmatic management. Tools like the Knock CLI and Knock MCP server mean you can automate your implementation using tools like Cursor or Claude Code.
Knock is built as infrastructure to handle billions of notifications with guaranteed delivery and idempotency. While Loops can handle large volumes, it's optimized for email campaigns rather than real-time, event-driven notifications at scale across multiple channels.
Loops primarily focuses on email marketing and transactional emails. Knock supports email, SMS, push notifications, in-app messaging, and chat apps like Slack, Microsoft Teams, and WhatsApp, plus webhooks for custom channels.
Only Knock allows integration flexibility with 25+ messaging providers, allowing teams to take advantage of unique benefits of individual services. For example, AWS-native companies can save costs by using Amazon SES to send transactional emails or use Twilio's infrastructure to reach 180+ countries via SMS.
Yes, many companies use both platforms. It's common to see engineering teams using Knock to handle transactional messaging (alerts, updates, collaboration messages) while marketing teams use Loops to manage email marketing campaigns.
However, this separation can lead to inconsistent messaging over time, and using two systems ends up costing more than just using Knock to handle all product and customer messaging.
Knock typically offers more cost-effective pricing for teams building holistic messaging systems. While Loops requires tiered subscriptions based on contacts, Knock provides transparent usage-based pricing starting at $0 for the first 10,000 notifications, making it accessible for startups and growing companies, with volume discounts for larger enterprise organizations.
All plans include unlimited data ingestion and unlimited channels with no onboarding or service fees, and overages are only incurred by volume of sent messages.
Both platforms offer enterprise compliance features. Knock provides SOC 2 Type 2 certification and supports GDPR/CCPA requirements. Loops offers similar compliance but typically requires enterprise contracts.
Knock is designed for rapid implementation by developers, with most teams shipping notifications within hours using pre-built components. Loops typically requires weeks of migration, configuration, and training for marketing teams.
Most engineering teams migrate from Loops to Knock within 2-4 weeks, depending on notification complexity. Knock's developer-first approach and responsive support team help accelerate the process.