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APIs · head to head

Asyncapi vs Pusher

Asyncapi logo

Asyncapi

APIs

Specification and tools for defining asynchronous APIs

From
Free
Rated
-
Full reviewWebsite
Pusher logo

Pusher

APIs

Realtime messaging API for building live features into apps

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Asyncapi complex to implement and debug asynchronous operations due to their non-linear and concurrent nature; Pusher the free Sandbox plan is capped at 100 concurrent connections, which is quickly outgrown by production apps.
  • They diverge on capability: Asyncapi covers API Specification, Pusher covers Pub/sub channels.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Asyncapi and Pusher actually diverge.

Attributes where Asyncapi and Pusher differ
AttributeAsyncapiPusher
Pricing modelopen-sourcefreemium
PlatformsWeb, CLI, IDE Extensionsweb, ios, android, api
Founded2019Unknown

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated), category (APIs).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Asyncapi

  • API Specification
  • Code generation
  • Documentation
  • Multiple messaging protocols
  • Code generators
  • Specification support
  • Tools support
  • CLI support

Only in Pusher

  • Pub/sub channels
  • Presence channels
  • Client libraries
  • Webhooks
  • 24/7 monitoring
  • Priority support

What people use each for

The jobs each tool is most often brought in to do.

Asyncapi

  • API Developmentnot Pusher
  • API Gatewaynot Pusher
  • API Testingnot Pusher
  • API Documentationnot Pusher
  • Microservicesnot Pusher

Pusher

  • Adding live chat to a web or mobile appnot Asyncapi
  • Showing realtime presence of online usersnot Asyncapi
  • Pushing live notifications or dashboard updatesnot Asyncapi
  • Building collaborative features without managing WebSocket serversnot Asyncapi

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Asyncapi

  • Complex to implement and debug asynchronous operations due to their non-linear and concurrent nature
  • Keeping AsyncAPI documents up to date is challenging as systems evolve
  • Tracing and debugging asynchronous operations is more difficult than synchronous request-response patterns

Pusher

  • The free Sandbox plan is capped at 100 concurrent connections, which is quickly outgrown by production apps.
  • Pricing jumps sharply between tiers (e.g. $49 to $99 to $299), leaving few options for teams with moderate but growing usage.
  • Priority support with faster response times costs an additional $3,000/month on top of plan pricing.

Pricing, plan by plan

Asyncapi

Free
  • Open SourceFree
    • AsyncAPI specification
    • Tools
    • Community support

Pusher

Free
  • SandboxFree
    • 200k messages/day
    • 100 concurrent connections
    • Standard support
  • Startup$49/month
    • 1M messages/day
    • 500 concurrent connections
  • Pro$99/month
    • 4M messages/day
    • 2,000 concurrent connections
  • Business$299/month
    • 10M messages/day
    • 5,000 concurrent connections
    • Premium support

Which should you pick?

Choose Asyncapi if

  • You need api specification.
  • You want to start without paying.
  • You work on Web, CLI, IDE Extensions.
  • You also want code generation.
Asyncapi review

Choose Pusher if

  • You need pub/sub channels.
  • You want to start without paying.
  • You work on web, ios, android, api.
  • You also want presence channels.
Pusher review

Questions people ask

Is Asyncapi or Pusher better?
Neither clearly leads. Asyncapi starts at Free and Pusher at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Asyncapi or Pusher?
Asyncapi starts at Free and Pusher at Free.
Does Asyncapi or Pusher run on more platforms?
Asyncapi runs on Web, CLI, IDE Extensions. Pusher runs on web, ios, android, api.
Can I use Asyncapi for free?
Both have a free tier, so you can try either at no cost before committing.
What is Asyncapi best used for?
Asyncapi is most often used for api development, api gateway, api testing, api documentation. Of those, api development and api gateway are not what Pusher is typically brought in for.
What can Asyncapi do that Pusher cannot?
Asyncapi covers API Specification, Code generation, Documentation, Multiple messaging protocols. Pusher covers Pub/sub channels, Presence channels, Client libraries, Webhooks.

Answered from the vendors’ own pages

Asyncapi: What is AsyncAPI used for?

AsyncAPI is an open-source specification for defining and documenting asynchronous APIs, message-driven systems, and event-driven architectures. It serves the same purpose for async APIs as OpenAPI does for REST APIs, providing standardized documentation, code generation, and tooling.

Source
Pusher: What does Pusher cost?

Pusher Channels offers a free Sandbox plan (200k messages/day, 100 connections) and paid plans starting at $49/month for Startup, scaling up through Pro, Business, and several higher tiers up to $1,199/month, plus custom Enterprise pricing.

Source
Asyncapi: Is AsyncAPI free to use?

Yes, AsyncAPI is completely free and open-source. It is hosted by the Linux Foundation and supported by community contributions and sponsorships from companies like Postman, IBM, IQVIA Technology, and Solace.

Source
Pusher: Can I change or cancel my plan?

Yes, customers can log into the dashboard and adjust their plan at any time, including upgrading, downgrading, or cancelling.

Source
Asyncapi: What protocols and technologies does AsyncAPI support?

AsyncAPI supports multiple protocols and technologies including Kafka, RabbitMQ, MQTT, Socket.IO, AWS EventBridge, and others. It provides language support for JavaScript/TypeScript, Python, Java, Go, C#/.NET, Kotlin, and PHP.

Source
Pusher: How is usage metered?

Usage is measured by concurrent connections and messages per day; a message counts both the publish and each delivery, so publishing one message to 50 subscribers counts as 51 messages.

Source
Asyncapi: Does AsyncAPI have IDE support?

Yes, AsyncAPI has IDE extensions available for VSCode and IntelliJ, along with CLI utilities and GitHub Actions integration for developers.

Source
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