NotifKit vs SuprSend

SuprSend is a proprietary cloud notification platform with web campaign builders and usage-based tiers. NotifKit is an open-source, self-hosted engine on PostgreSQL and Redis Streams, with full queue visibility, modular TypeScript providers and no platform fees.

The short version

SuprSend targets product and growth teams managing multi-channel campaigns through a web UI. As a closed-source SaaS, it stores your customer data on its servers, its queues are black boxes, and volume spikes trigger costly overages.

NotifKit gives developers direct control. Queues, delivery logs, dead letters and preference rules live in your own database, with modular transports you can inspect and customise in TypeScript.

Feature comparison

Pricing & total cost of ownership (TCO)

SuprSend has a free tier (10k notifications/mo), an Essentials plan at $100/month (50,000 notifications/mo included) and a Business plan at $250/month, with overage at $0.002/msg on Essentials and $0.005/msg on Business. Provider rates (Twilio SMS, Resend, AWS SES, FCM Push) come on top.

Monthly TCO by notification volume

Monthly TCO by volume, with a standard channel mix (10% Twilio SMS @ $0.0079, 70% Resend/SES Email @ $0.0001–$0.0008, 20% FCM Push @ $0):

Key differences deep-dive

1. Transparent Redis Stream mechanics vs black-box SaaS

When delivery fails on a proprietary cloud aggregator, finding out why a message was dropped or delayed often means a support ticket or opaque webhook errors.

NotifKit's delivery engine runs across distinct Redis Streams:

Inbound Stream → Enricher → Outbound Stream → Delivery Worker → Gateway (Resend/Twilio/FCM)
                                                    ↳ Retry / DLQ Stream

Priorities are separate physical streams (critical, normal, low), so bulk campaigns can't starve urgent authentication codes. A permanently failed delivery lands in the Dead-Letter Queue (/v1/dlq) to inspect, replay or debug.

2. Extensibility with modular TypeScript packages

Adding a transport or internal webhook needs no proprietary plugin marketplace. Every transport implements one TypeScript contract:

import type { Transport, NotificationDispatchedPayload, DeliveryResult } from "notifkit";

export class CustomSmsTransport implements Transport {
  readonly channel = "sms" as const;

  async send(task: NotificationDispatchedPayload): Promise {
    if (!task.destination) {
      return { success: false, error: "no destination resolved for sms" };
    }

    const content = task.renderedContent.content as Record;
    const body = (content.text ?? content.body) as string | undefined;
    if (!body) return { success: false, error: "template produced no text" };

    const response = await fetch("https://internal-sms-gateway.company.com/send", {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({
        to: task.destination,
        message: body,
      }),
    });

    if (!response.ok) {
      return { success: false, retryable: response.status >= 500, error: await response.text() };
    }

    return { success: true, providerMessageId: (await response.json()).id };
  }
}

When to choose what