Softwr

APIs · head to head

Asyncapi vs Svix

Asyncapi logo

Asyncapi

APIs

Specification and tools for defining asynchronous APIs

From
Free
Rated
-
Full reviewWebsite
Svix logo

Svix

APIs

Outbound webhook sending as a service, with retries, signing and a customer-facing portal

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; Svix the Professional tier at 490 US dollars a month includes the same 50,000 messages as the free tier, so the upgrade buys SLA, throughput and retention rather than volume, which is a jarring step for a growing product.
  • They diverge on capability: Asyncapi covers API Specification, Svix covers Automatic retries.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Asyncapi and Svix actually diverge.

Attributes where Asyncapi and Svix differ
AttributeAsyncapiSvix
Pricing modelopen-sourcePer month by message count
PlatformsWeb, CLI, IDE ExtensionsWeb, Cloud, Docker
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 Svix

  • Automatic retries
  • Payload signing
  • Consumer portal
  • Event types and filtering
  • Delivery logs and replay
  • Rate limiting
  • Static source IPs
  • Language SDKs

What people use each for

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

Asyncapi

  • API Developmentnot Svix
  • API Gatewaynot Svix
  • API Testingnot Svix
  • API Documentationnot Svix
  • Microservicesnot Svix

Svix

  • A SaaS company adding webhooks to its API that does not want to build retry, signing and a customer debugging UI from scratchnot Asyncapi
  • A payments or fintech product whose customers need signature verification libraries in several languages they did not writenot Asyncapi
  • An engineering team drowning in support tickets from customers whose endpoints silently failed and who need self-service delivery logsnot Asyncapi
  • A platform with a small number of very slow customer endpoints that must not delay deliveries to everyone elsenot 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

Svix

  • The Professional tier at 490 US dollars a month includes the same 50,000 messages as the free tier, so the upgrade buys SLA, throughput and retention rather than volume, which is a jarring step for a growing product.
  • Only attempted messages count toward usage, but a customer with many subscribed endpoints multiplies a single event into many billable messages, and forecasting that fan-out before launch is difficult.
  • The open source server is MIT licensed but trails the hosted product in features, so self-hosting is a fallback position rather than a genuinely equivalent option.
  • Routing outbound customer traffic through a third party puts a vendor in the delivery path for events your customers may treat as contractual, which some security reviews will not accept.
  • Payload retention is 30 days on the free tier and 90 on Professional, so anyone needing longer delivery history for audit must pay for Enterprise or log independently.

Pricing, plan by plan

Asyncapi

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

Svix

Free
  • FreeFree
    • 50,000 messages a month included
    • Overage at $0.0001 per message
    • 99.9% uptime SLA
  • Professional$490/month
    • 50,000 messages included, same as free
    • 99.99% uptime SLA
    • 800 messages per second
  • Enterprise$undefined/year
    • Custom volume and rate limits
    • 99.999% uptime SLA
    • Custom retention

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 Svix if

  • You need automatic retries.
  • You want to start without paying.
  • You work on Web, Cloud, Docker.
  • You also want payload signing.
Svix review

Questions people ask

Is Asyncapi or Svix better?
Neither clearly leads. Asyncapi starts at Free and Svix at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Asyncapi or Svix?
Asyncapi starts at Free and Svix at Free.
Does Asyncapi or Svix run on more platforms?
Asyncapi runs on Web, CLI, IDE Extensions. Svix runs on Web, Cloud, Docker.
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 Svix is typically brought in for.
What can Asyncapi do that Svix cannot?
Asyncapi covers API Specification, Code generation, Documentation, Multiple messaging protocols. Svix covers Automatic retries, Payload signing, Consumer portal, Event types and filtering.

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
Svix: How much does Svix cost?

Free up to 50,000 messages a month; Professional starts at 490 US dollars a month with the same included volume but better SLA and throughput.

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
Svix: Can I self-host it?

Yes, there is an MIT licensed server, but it lags the hosted service in features and has no SLA.

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
Svix: What counts as a message?

Attempted or transformed deliveries. Retries and messages filtered out because no endpoint subscribed are not charged.

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
Svix: Does it handle inbound webhooks?

Its focus is outbound sending on behalf of API providers, not receiving webhooks from third parties.

Share

Related pages

More on Asyncapi

More on Svix

Keep looking

Other head to heads