Free-tier realtime & messaging

GraphComment

GraphComment is a web commenting platform that embeds a discussion widget on a website and supports threaded replies, votes, shares, media embedding, text formatting, notifications, moderation tools, and multilingual interfaces.

Aiven

Aiven is a managed open source data platform that provides hosted Kafka, PostgreSQL, MySQL, ClickHouse, OpenSearch, Valkey, Metrics, and Grafana services across major cloud providers. The platform inc...

Novu

Novu is an open-source notifications infrastructure platform for developers and product teams. It provides APIs, SDKs, and UI components for building in-app notification inboxes and orchestrating mult...

Hook0

Hook0 is an open-source webhooks-as-a-service platform that lets developers send webhook events through a REST API. It handles delivery attempts, retries, HMAC signatures, TLS encryption, replay defense, monitoring, and replay from a dashboard or API.

CloudAMQP

CloudAMQP is a managed message broker service for LavinMQ and RabbitMQ clusters. It automates cluster setup, operation, scaling, monitoring, and upgrades across major cloud platforms, with a control panel for alarms, logs, diagnostics, and user management.

Element

Element is a secure communications platform built on the Matrix open standard. It provides self-hosted and air-gapped messaging, voice and video calls, federation between separate organisations, and administrative controls for enterprise and public-sector deployments.

Emitlo

Emitlo is an email delivery service that provides a REST API and SMTP relay for transactional and marketing email. It supports sending through POST /api/v1/messages or SMTP credentials, with DKIM, SPF, and DMARC authentication, real-time analytics, HMAC-signed webhooks, and delivery event tracking.

Stoat

Stoat is an open-source group chat application for friends and communities. It provides servers, channels, voice chat, file sharing, markdown support, role-based permissions, moderation tools, bots, a...

Stream

Stream provides APIs and SDKs for building real-time chat messaging, video and audio calling, activity feeds, AI moderation, and Vision Agents. The platform includes shared infrastructure, prebuilt UI...

Simperium

Simperium is a cross-platform data sync service for application data. It provides APIs and libraries for iOS, Android, JavaScript, Python, Ruby, HTTP, and WebSocket clients so apps can keep data synchronized across platforms.

Gitter

Gitter is a chat and networking platform for developer communities. It runs on Matrix and connects to the gitter.im homeserver, so users can access rooms through the Gitter web app or any Matrix client they prefer.

Scaledrone

Scaledrone is a realtime messaging service that provides WebSocket-based pub/sub messaging, message history, and user presence for applications that need live updates. The service supports publishing messages, subscribing to rooms, and fallback transport handling when WebSockets are not available.

Hookdeck Event Gateway

Hookdeck Event Gateway is a webhook and event ingestion service that receives inbound HTTP requests, applies routing and filtering rules, queues events, and delivers them to downstream destinations. I...

ConnectyCube

ConnectyCube provides chat and calling SDKs for developers building messaging, voice, and video features into applications. The platform includes SDKs and APIs for Flutter, React Native, Web, Cordova,...

Chanty

Chanty is a team communication and collaboration platform with chat, voice and video calls, task management, file sharing, and integrations. It supports unlimited public and private chats, unlimited a...

talky

Talky is a browser-based video chat and screen sharing service that creates a unique room URL for each call. Users enter a name or start a chat, then share the room link with up to 6 participants who join through a supported browser without creating personal accounts.

Pingram

Pingram is a messaging API platform for sending and receiving email, SMS, voice calls, and WhatsApp messages through a single send-oriented API. The landing page shows outbound message payloads for email, SMS, voice, and WhatsApp, plus inbound processing, logs, and integrations.

HiveMQ Cloud

HiveMQ Cloud is a fully managed MQTT broker platform hosted by HiveMQ. It provides a serverless free plan for learning and experimentation, plus paid Starter and Enterprise plans for larger deployments.

Engage

Engage is a customer engagement platform for SaaS teams that combines customer data, segmentation, messaging, automation, and support tools in one product. It includes a CDP, customer segmentation, mu...

AgentMail

AgentMail is an email inbox API for AI agents. It provides programmatic creation and management of email inboxes, threads, replies, attachments, realtime events, custom domains, semantic search, and data extraction through REST APIs, SDKs, webhooks, and MCP support.

Flock

Flock is a team messaging and collaboration platform with channels, direct messages, voice and video calling, file sharing, to-dos, polls, reminders, and integrated search. It provides desktop apps for Windows, Mac, Linux, and Chrome, plus web access through the Flock service.

Engagespot

Engagespot is a notification infrastructure platform for developers. It provides a single API for sending in-app, email, push, SMS, Slack, Discord, WhatsApp, and webhook notifications, along with templates, workflows, provider management, logging, and a built-in real-time in-app inbox.

Svix

Svix is a webhook infrastructure service for sending, receiving, and testing webhooks through an API and dashboard. It includes webhook dispatch, webhook ingestion, and Svix Play for inspecting and de...

LeanCloud

LeanCloud is a serverless backend platform that provides database storage, server-side logic with LeanEngine, instant messaging, push notifications, SMS, and multiplayer game services. It supports nat...

ScreenSharing

ScreenSharing is a browser-based screen sharing service that lets a user start a session from the web, choose a screen or application window, and share a generated link with viewers. The page describe...

Webpushr

Webpushr is a web push notifications platform that lets websites send browser push messages through a dashboard, REST API, or WordPress plugin. The service supports subscriber targeting by segments an...

SuprSend

SuprSend is a notification infrastructure platform for sending and managing multi-channel notifications across email, SMS, Slack, push, web push, WhatsApp, in-app inbox, and webhooks. It provides work...

Ably is a realtime messaging platform that provides pub/sub APIs, chat, AI transport, live objects, spaces, and live sync for applications that need low-latency updates and state synchronization. The ...

Liveblocks

Liveblocks is a realtime infrastructure platform for multiplayer apps and collaborative AI workflows. It provides hosted primitives for presence, broadcast events, synced storage, feeds, and threads, ...

Pusher

Pusher provides hosted realtime APIs for building features such as live updates, pub/sub messaging, in-app chat, location tracking, and push notifications. Its Channels product supports publish/subscribe messaging across web and mobile clients, while Beams handles programmatic push notifications.

PartyKit is an open source deployment platform for AI agents, multiplayer and local-first apps, games, and websites. It provides a server-side runtime for WebSockets, Fetch request/response handlers, and Wasm, with a CLI for local development and edge deployment.

Amazon SNS

Amazon Simple Notification Service (SNS) is a fully managed pub/sub messaging service from AWS that helps applications send notifications and distribute events at scale.