Realtime & push

Firebase · No-cost

Cross-platform push notifications and data messages for Android, Apple and web apps, at no cost on every Firebase plan, including Spark, which needs no payment details. Sending is rate-limited to a default 600,000 messages a minute per project.

• Unlimitedmonthly active users
• 600Kdownstream messages per project / minute
• 3Ktopic subscription changes per project / second

• Commercial use
• Can't bill you
• No card
• Blocked in China

Ably · Free

6 million messages a month, 200 concurrent connections, 200 concurrent channels and 500 messages a second across one account, with presence, one day of message history and mobile and web push. Meant for trying Ably and building a proof of concept; no card needed and no time limit.

• 6Mmessages / month
• 500messages per second / second
• 250Kmessages per hour / hour

• Commercial use restricted
• Can't bill you
• No card

Novu · Free

10,000 workflow runs a month on hosted Novu, with 20 workflows, Development and Production environments, 3 team members and a US or EU data region. A run notifies one subscriber on any mix of in-app Inbox, email, SMS, push and chat; all but in-app go out through providers you connect, as the built-in demo email and SMS providers are test-only. Activity logs are kept 24 hours. No card needed.

• 10Kworkflow runs / month
• 3team members
• 1 dActivity Feed logs

• Commercial use
• Can't bill you
• No card

Expo · Free

Expo's hosted push API delivers notifications to Android and iOS apps through FCM and APNs at no cost. It needs an Expo account and your own FCM and APNs credentials. Sending is limited to 600 notifications a second per project and 100 per request, push receipts are cleared after 24 hours, and Expo's Free plan is meant for pre-revenue, hobby and student projects.

• 600notifications per project / second
• 24 hpush receipts

• Commercial use restricted
• Can't bill you

Liveblocks · Free

Free plan for realtime collaboration (presence, broadcast, storage, comments, notifications): unlimited monthly active users, 10 concurrent connections per room, 3,000 collaboration minutes and 3M storage updates a month, 1 GB of room data and 512 MB of files. Usage limits are hard caps that pause a feature until next month. No card needed; fair use rules limit Free to non-commercial projects.

• 10concurrent connections per room
• 3Kanonymous connections / month
• Unlimitedmonthly active users

• Non-commercial only
• Stops at the limit
• No card

OneSignal · Free

Unlimited mobile push and in-app messages for organizations with up to 1,000 mobile monthly active users (trailing 30 days), web push to unlimited subscribers with up to 10,000 per send, and 10,000 email sends a month. Above 1,000 MAU, mobile push and in-app messages stop after 24 hours until you upgrade.

• 1Kmobile monthly active users
• Unlimitedmobile push notifications / month
• Unlimitedin-app messages / month

• Commercial use
• Stops at the limit

Pusher · Sandbox

Free Beams plan for iOS, Android and web push notifications: up to 1,000 subscribers (devices registered to receive notifications), counted concurrently across all your Beams instances. Pusher's tutorials say free-plan notifications are unlimited, and the Publish API takes up to 100 requests a second. Over the subscriber limit, Pusher emails you daily and publishing can be blocked with HTTP 402.

• Unlimitedpush notifications / month
• 1Ksubscribers (devices)
• 100Publish API requests / second

• Stops at the limit

Pusher · Sandbox

Free Channels plan for realtime pub/sub over WebSockets: 200,000 messages a day and 100 concurrent connections, with up to 10 KB of data per message. Every message Pusher receives or delivers counts, so one publish to 50 subscribers uses 51; on Sandbox, connections over the limit are rejected immediately.

• 200Kmessages / day
• 100connections at once
• 0.01 MBmessage size

• Commercial use
• Stops at the limit

PubNub · Free

PubNub's realtime network (pub/sub, presence, message history, mobile push and Functions) for up to 200 monthly active users or 1 million transactions a month, whichever comes first, with no cap on channels or connections. Free accounts get up to 3 rate-limited Testing keysets, meant for development rather than live traffic.

• 1Mmobile push notifications / month
• Unlimitedconcurrent connections
• 200monthly active users

• Commercial use restricted
• No card

Knock · Developer

Free cross-channel notification plan: 10,000 messages a month across in-app feeds, push, email, SMS and chat, with unlimited workflows, environments, team members and recipients, and 30 days of logs. Push, email and SMS go out through provider accounts you connect, such as FCM, APNs or Expo. Knock doesn't hard-cap usage: past the limit it asks you to add billing.

• 10Kmessages sent (1 per user per channel) / month
• Unlimitedteam members
• Unlimitedenvironments

• Commercial use
• Bills overage
• No card