Convex
The reactive backend platform that keeps your UI in sync with your data — with built-in AI support.
Convex Review: The Backend Platform Built for Real-Time Apps and AI Workloads
Most backend platforms require developers to manage the complexity of keeping client state synchronised with server data — writing polling logic, WebSocket management, or cache invalidation code that makes every real-time feature a significant engineering effort. Convex eliminates this entirely through its reactive architecture, where any change to the database automatically pushes updates to every connected client subscribed to queries affected by that change — with no additional code required. Combined with built-in AI action support for calling LLMs and vector search for semantic retrieval, Convex has become the backend of choice for developers building AI-powered real-time applications.
Quick Summary
Convex is a reactive backend-as-a-service platform providing a real-time database, serverless TypeScript functions, automatic client synchronisation, built-in vector search, and AI action support for building modern full-stack and AI-powered applications.
Is it worth using? Yes for TypeScript developers building real-time applications or AI-powered features who want automatic client-server synchronisation without managing WebSockets or cache invalidation manually.
Who should use it? Full-stack TypeScript developers, indie hackers, and engineering teams building real-time collaborative applications or AI features who want backend infrastructure that handles synchronisation automatically.
Who should avoid it? Teams with existing backend infrastructure they are happy with, or developers working outside TypeScript where Convex’s type-safe client does not apply.
Verdict Summary
Best for
- TypeScript developers building real-time features — collaborative editing, live updates, chat, notifications — who want automatic client synchronisation without WebSocket management
- Developers building AI-powered applications who need vector search and LLM action support alongside their application database in one platform
- Indie hackers and small teams who want a complete, type-safe backend without managing separate database, API, and real-time infrastructure
Not for
- Teams working outside TypeScript where Convex’s type safety advantages do not apply
- Applications requiring the most granular database query control that raw SQL provides
- Teams with existing backend infrastructure where Convex adoption creates unnecessary migration overhead
Rating
⭐⭐⭐⭐ 4.4 / 5
What Is Convex?
Convex is a backend platform that provides a document database with a TypeScript query API, serverless functions for backend logic, and a reactive subscription system that keeps client state automatically synchronised with database state. When a document changes in the Convex database, every client query that reads that document is automatically re-run and the results pushed to connected clients — no WebSockets to manage, no polling to implement, no cache to invalidate.
Its AI features include vector search for storing and querying embeddings alongside regular document queries, and AI actions — serverless functions with longer execution windows and HTTP access for calling external LLM APIs — enabling AI-powered features to be built as first-class Convex functions alongside regular application logic.
How Convex Works
- Define your schema. Write your data model in TypeScript using Convex’s schema definition system, giving you full type safety throughout the backend and generated TypeScript types for the client.
- Write server functions. Define queries (read-only), mutations (read-write), and actions (external API calls including LLMs) as TypeScript functions. Queries are automatically reactive.
- Use the client in your frontend. Import Convex’s React hooks in your frontend.
useQueryhooks subscribe to query results and re-render automatically when the underlying data changes. - Build AI features with actions. Write Convex actions that call OpenAI, Anthropic, or other LLM APIs, returning results that feed into your application database and trigger reactive updates to connected clients.
- Use vector search for semantic retrieval. Store embeddings in Convex’s built-in vector index and run similarity searches alongside regular database queries for AI retrieval-augmented generation (RAG) features.
- Deploy automatically. Convex handles hosting, scaling, and infrastructure. Push new function code and schema changes are deployed instantly without server management.
Key Features
- Reactive database with automatic client state synchronisation on data change
- TypeScript-first with end-to-end type safety from schema to client hooks
- Queries, mutations, and actions as serverless TypeScript functions
- Built-in vector search for AI embedding storage and semantic retrieval
- AI actions with extended timeouts for LLM API calls
- React hooks for real-time data subscription without WebSocket management
- Scheduled functions for cron-like recurring backend tasks
- File storage integrated into the backend platform
- Dashboard for monitoring function executions, database state, and logs
Real-World Use Cases
- Real-time collaborative tool: A productivity app uses Convex’s reactive queries to keep all connected users’ views synchronised — when one user updates a document, every other user sees the change instantly without any WebSocket code on either side.
- AI chat application: A developer builds a chat application where user messages trigger Convex actions that call the OpenAI API, stream the response back through the database, and update every connected client’s chat view reactively as tokens arrive.
- RAG-powered search: An application uses Convex vector search to store document embeddings and run semantic similarity queries, combining traditional database filters with vector similarity in a single Convex query for retrieval-augmented generation features.
- Real-time dashboard: A SaaS analytics dashboard uses Convex reactive queries to keep all metrics updated live as new data arrives — eliminating the polling logic that traditional dashboards require to show current data.
Pros and Cons
| Pros | Cons |
|---|---|
| Automatic client synchronisation eliminates WebSocket and polling boilerplate | TypeScript-only — limited value for non-TypeScript development stacks |
| Built-in AI features — vector search and LLM actions — without separate infrastructure | Document model less flexible than relational SQL for complex query patterns |
| End-to-end type safety from database schema to React hooks is genuinely valuable | Newer platform with smaller community than Supabase or Firebase |
| Reactive architecture makes real-time features dramatically simpler to build | Some applications benefit from more granular database control than Convex provides |
| Free tier is generous for development and small production use | Platform is less proven at very large scale than established alternatives |
Pricing & Plans
Free — $0/month
- Generous function call limits
- Database storage included
- Vector search
- Community support
Pro — $25/month
- Higher function call limits
- More database storage
- Priority support
- Advanced features
Enterprise — Custom pricing
- Custom limits
- Dedicated support
- SLA guarantees
Best Alternatives & Comparisons
- Supabase — Better for teams wanting PostgreSQL with full SQL power alongside auth and storage, less reactive out of the box
- Firebase — Similar reactive real-time database with broader mobile SDK support, NoSQL document model
- Neon — Better for serverless PostgreSQL specifically without a full backend platform
- PlanetScale — Better for MySQL at scale with non-blocking migrations, not a reactive backend platform
Frequently Asked Questions (FAQ)
Convex is a reactive backend-as-a-service platform providing a real-time database, serverless TypeScript functions, automatic client synchronisation, vector search, and AI action support for building modern full-stack and AI-powered applications.
Yes, Convex offers a generous free tier. The Pro plan at $25/month provides higher limits and priority support.
In Convex, read queries are automatically subscribed to by connected clients. When any data the query reads changes, Convex re-runs the query and pushes updated results to every subscribed client automatically — eliminating the need for polling, WebSocket management, or manual cache invalidation.
Yes, Convex has built-in AI support through vector search for embedding storage and semantic retrieval, and actions — serverless functions with extended timeouts — for calling OpenAI, Anthropic, and other external LLM APIs as part of application workflows.
Convex uses a reactive document database with automatic client synchronisation. Supabase uses PostgreSQL with manual real-time subscription setup. Convex is better for real-time applications where automatic synchronisation removes significant boilerplate. Supabase is better for teams who want relational SQL power and a more complete backend platform covering auth, storage, and edge functions.
Convex has first-class React support through its hooks library. It also supports Next.js, Vue, Svelte, and other frameworks through its JavaScript client. The React hooks provide the most seamless reactive experience.
Final Recommendation
Convex is the most innovative backend platform for TypeScript developers building real-time applications or AI-powered features who want the automatic client synchronisation that eliminates the most tedious parts of real-time application development. The combination of reactive queries, built-in vector search, and AI actions in one TypeScript-native platform creates a backend experience that significantly reduces the engineering overhead of modern application development. For any developer building real-time or AI features who is tired of managing WebSockets and cache invalidation, Convex provides the architectural solution that makes those problems disappear.
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