List of free real-time stuff for developerππ½
If you're looking for all programming tools around real-time (not just free). Check this page List of real-time Programming Tools

Liveblocks
Liveblocks is a set of APIs and tools that helps you create performant and reliable collaborative experiences.
Tag: real-time, collaboration
Unlimited rooms 30 simultaneous connections 5 simultaneous connections per room Community support

Ably Realtime
Ably provides a suite of APIs to build, extend, and deliver powerful digital experiences in realtime.
Tag: real-time
6m monthly messages 200 peak connections 200 peak channels

Scaledrone Realtime Messaging Service
Scaledrone is a realtime messaging service and platform. Send live updates, create chatrooms and collaborative tools.
Tag: real-time
Free Plan 100,000 daily events 20 concurrent users.
Pusher
Simple, scalable and reliable. Hosted realtime APIs loved by developers and trusted by giants. Build live dashboards, notifications, geotracking, chat and more.
Tag: real-time
Sandbox Account 200k messages/day 100 Concurrent connections

Pusher Beams
A push notifications API for developers who need critical information delivered every time. Scalable delivery for all your apps with no complex integration.
Tag: real-time, push-notification
Sandbox Account 1,000 subscribers

Firebase
Firebase helps you build and run successful apps Backed by Google and loved by app development teams - from startups to global enterprises
Tag: database, hosting, hosting-dynamic, hosting-static, storage, authentication, real-time
Authentication 10k/month Cloud Firestore (stored data: 1 GiB total) Realtime Database (stored data: 1 GB) Hosting storage 10 GB Cloud storage 5 GB
Knock
Knock is flexible, reliable notifications infrastructure that's built to scale with you.
Tag: real-time, push-notification
10,000 Free notifications per month Unlimited team members Unlimited notification workflows Preferences support Batch and delay functions

Supabase
The Open Source Firebase Alternative Create a backend in less than 2 minutes. Start your project with a Postgres Database, Authentication, instant APIs, realtime subscriptions and Storage.
Tag: database, storage, authentication, real-time
Get free database, authentication and storage Unlimited API request Database space (Up to 500MB) Users 10.000 users Social Auth provider Storage Up to 1GB Transfer Limit Up to 2GB Team members: unlimited

Socket.IO
Socket.IO enables real-time, bidirectional and event-based communication. It works on every platform, browser or device, focusing equally on reliability and speed.
Tag: real-time

PocketBase
Open Source backend in 1 file with realtime database, authentication, file storage and admin dashboard
Tag: database, hosting, hosting-dynamic, hosting-static, storage, authentication, real-time
Open Source, self hosted

Realm
Realm is a fast, scalable alternative to SQLite with mobile to cloud data sync that makes building real-time, reactive mobile apps easy.
Tag: database, real-time

Emitter
Emitter is a real-time communication service for connecting online devices. The Publish-Subscribe messaging API is built for speed and security.
Tag: real-time