BaaS

• Activepieces - Build automation flows to connect several apps together in your app’s backend. For example, send a Slack message or add a Google Sheet row when an event fires in your app. Free up to 5,000 tasks per month.
• back4app.com - Back4App is an easy-to-use, flexible and scalable backend based on Parse Platform.
• backendless.com — Mobile and Web Baas, with 1 GB file storage free, push notifications of 50,000/month, and 1000 data objects in the table.
• bismuth.cloud — Our AI will boostrap your Python API on our function runtime and hosted storage, build and host for free in our online editor or locally with your favorite tools.
• BMC Developer Program — The BMC Developer Program provides documentation and resources to build and deploy digital innovations for your enterprise. Access to a comprehensive, personal sandbox that includes the platform, SDK, and a library of components that can be used to build and tailor apps.
• connectycube.com - Unlimited chat messages, p2p voice & video calls, files attachments and push notifications. Free for apps up to 1000 users.
• convex.dev - Reactive backend as a service, hosting your data (documents with relationships & serializable ACID transactions), serverless functions, and WebSockets to stream updates to various clients. Free for small projects - up to 1M records, 5M monthly function calls.
• darklang.com - Hosted language combined with editor and infrastructure. Accessible during the beta, a generous free tier is planned after beta.
• Firebase — Firebase helps you build and run successful apps. Free Spark Plan offers Authentication, Hosting, Firebase ML, Realtime Database, Cloud Storage, Testlab. A/B Testing, Analytics, App Distribution, App Indexing, Cloud Messaging (FCM), Crashlytics, Dynamic Links, In-App Messaging, Performance Monitoring, Predictions, and Remote Config are always free.
• Flutter Flow — Build your Flutter App UI without writing a single line of code. Also has a Firebase integration. The free plan includes full access to UI Builder and Free templates.
• getstream.io — Build scalable In-App Chat, Messaging, Video and audio, and Feeds in a few hours instead of weeks
• hasura.io — Hasura extends your existing databases wherever it is hosted and provides an instant GraphQL API that can be securely accessed for web, mobile, and data integration workloads. Free for 1GB/month of data pass-through.
• iron.io — Async task processing (like AWS Lambda) with free tier and 1-month free trial
• nhost.io - Serverless backend for web and mobile apps. The free plan includes PostgreSQL, GraphQL (Hasura), Authentication, Storage, and Serverless Functions.
• onesignal.com — Unlimited free push notifications. 10,000 email sends per month, with unlimited contacts and access to Auto Warm Up.
• paraio.com — Backend service API with flexible authentication, full-text search and caching. Free for one app, 1GB of app data.
• progress.com — Mobile backend, starter plan has unlimited requests/second, with 1 GB of data storage. Enterprise application support
• pubnub.com — Free push notifications for up to 1 million messages/month and 100 active daily devices
• pushbots.com — Push notification service. Free for up to 1.5 million pushes/month
• pushcrew.com — Push notification service. Unlimited notifications for up to 2,000 Subscribers
• pusher.com — Free, unlimited push notifications for 2000 monthly active users. A single API for iOS and Android devices.
• quickblox.com — A communication backend for instant messaging, video, and voice calling, and push notifications
• restspace.io - Configure a server with services for auth, data, files, email API, templates, and more, then compose into pipelines and transform data.
• Salesforce Developer Program — Build apps Lightning fast with drag-and-drop tools. Customize your data model with clicks. Go further with Apex code. Integrate with anything using powerful APIs. Stay protected with enterprise-grade security. Customize UI with clicks or any leading-edge web framework. Free Developer Program gives access to the full Lightning Platform.
• ServiceNow Developer Program — Rapidly build, test, and deploy applications that make work better for your organization. Free Instance & access to early previews.
• simperium.com — Move data everywhere instantly and automatically, multi-platform, unlimited sending and storage of structured data, max. 2,500 users/month
• Singlebase.cloud — SinglebaseCloud is an AI-powered all-in-one backend platform to accelerate app development. It offers tools like Vector DB, Relational Document DB, Auth, Search, and Storage, aiming to simplify backend development. Free/Starter Plan offers Relational Document DB, Auth, Search, Storage.
• stackstorm.com — Event-driven automation for apps, services, and workflows, free without flow, access control, LDAP
• streamdata.io — Turns any REST API into an event-driven streaming API. Free plan up to 1 million messages and ten concurrent connections.
• Supabase — The Open Source Firebase Alternative to build backends. Free Plan offers Authentication, Realtime Database & Object Storage.
• tyk.io — API management with authentication, quotas, monitoring and analytics. Free cloud offering
• zapier.com — Connect the apps you use to automate tasks. Five zaps every 15 minutes and 100 tasks/month
• IFTTT — Automate your favorite apps and devices. Free 2 Applets
• Integrately — Automate tedious tasks with a single click. Free 100 Tasks, 15 Minute Update Time, five active automations, webhooks.
• LeanCloud — Mobile backend. 1GB of data storage, 256MB instance, 3K API requests/day, and 10K pushes/day are free. (API is very similar to Parse Platform)