Overview

Sendy and Loops represent different approaches to email marketing. Sendy is a proven, cost-effective self-hosted tool. Loops is a modern platform built specifically for SaaS companies. See our Loops comparison for more context.

Different Eras of Email

Sendy was built for a different era. It's PHP-based, requires self-hosting, and has basic automation. Loops is built for modern SaaS with event-based triggers, user properties, and clean APIs. The technology gap is significant.

Sendy's Cost Advantage

At 10,000 contacts, Sendy costs $1-5/month (Amazon SES fees only). Loops costs $149/month. Over a year, that's $1,700+ in savings. For budget-conscious senders with basic needs, Sendy's economics are compelling.

Loops' Modern Approach

Loops has event-based automation, user properties, product analytics integrations, and a developer-first API. You can trigger emails based on in-app behavior, not just email engagement. For product-led SaaS, this is the expected standard.

Technical Trade-offs

Sendy requires server administration, PHP hosting, and Amazon SES configuration. Loops is sign-up-and-go. The time spent on Sendy infrastructure could be spent on your product. But the cost savings are real.

Developer Experience

Loops has clean documentation, modern REST API, and good SDKs. Sendy has dated architecture and manual processes. For modern development teams, Loops integrates more naturally into your stack.

For SaaS with Stripe

Neither Sendy nor Loops has native Stripe integration. If payment-triggered automation is important for your SaaS, consider Sequenzy. We connect directly to Stripe for subscription-aware emails and revenue attribution.

Making the Choice

Choose Sendy if you're technical, have basic email needs, and want to minimize costs. Choose Loops if you're building a modern SaaS and want event-based automation with clean developer experience. For SaaS with Stripe billing, consider Sequenzy.

Generational Differences in Email Architecture

Sendy and Loops represent two distinct generations of email technology. Sendy is built on PHP/MySQL with a traditional web application architecture common in the early 2010s. Loops is built with modern infrastructure designed for real-time event processing, API-first interactions, and cloud-native deployment. The architectural gap affects every aspect of the user experience.

Sendy's architecture determines what it can do: store subscriber lists, schedule campaign sends, and track basic metrics. Loops' architecture enables what modern SaaS companies expect: ingest user events in real time, trigger automated workflows based on product behavior, personalize content using user properties, and manage transactional and marketing email through a unified API.

For developers evaluating these tools, the technical alignment matters. A modern SaaS application built with React, Node.js, and cloud infrastructure integrates naturally with Loops' REST API and event model. Integrating the same application with Sendy requires bridging the gap between modern and legacy architectures, often through workarounds that add complexity.

Event-Based Automation: The Feature That Changes Everything

The fundamental capability gap between Sendy and Loops is event-based automation. Loops can trigger emails when users complete specific actions in your product: creating their first project, inviting a team member, upgrading their plan, or hitting a usage milestone. Sendy can only trigger emails based on subscription to a list or time delays in a sequence.

For product-led SaaS companies, this difference is transformative. Onboarding emails that respond to actual user behavior outperform generic time-based sequences by significant margins. A user who has not created a project after three days needs a different message than one who created five projects on day one. Event-based automation enables this personalization. Time-based autoresponders cannot.

This capability directly impacts business metrics. Better onboarding emails improve activation rates. Behavior-triggered feature announcements increase adoption. Usage-based upgrade prompts drive revenue. These outcomes require event-based automation that Sendy architecturally cannot provide regardless of configuration.

The Developer Experience Gap

Loops' modern REST API with clean documentation, SDKs for popular languages, and webhook support creates a developer experience that Sendy cannot match. Integrating Loops into a modern application takes minutes with well-documented endpoints and predictable JSON responses.

Sendy's API is limited and dated. Basic operations like adding subscribers or sending campaigns are possible, but the API lacks the depth and documentation quality that modern developers expect. No webhooks, limited event support, and sparse documentation mean integration often requires trial and error.

For engineering teams that value developer experience, this gap affects velocity. Time spent wrestling with integration complexity is time not spent building your product. Loops' developer-first approach means email integration does not become a recurring engineering burden.

When Cost Savings Justify Feature Trade-offs

Despite Loops' superiority for SaaS use cases, Sendy's cost advantage creates legitimate scenarios where the simpler tool is the right choice. A bootstrapped founder sending a weekly product update to 5,000 subscribers does not need event-based automation. The $1,700+ annual savings versus Loops can fund other growth initiatives.

The calculus changes as the business matures. Once you have enough users that onboarding quality, feature adoption, and churn prevention measurably affect revenue, the investment in a capable email platform pays for itself. The question is not if you will need event-based automation, but when.

For SaaS companies that need event-based automation but find Loops' $149/month pricing steep, Sequenzy offers similar capabilities at $49/month with the added benefit of native Stripe integration. This positions Sequenzy as the middle ground: modern enough for SaaS needs, affordable enough for early-stage companies.