Softwr

APIs · head to head

Kong Gateway vs Swagger UI

Kong Gateway logo

Kong Gateway

APIs

Open-source and cloud API gateway for managing microservices traffic

From
Free
Rated
-
Full reviewWebsite
Swagger UI logo

Swagger UI

Developer Tools

Interactive API documentation generated from OpenAPI specs

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Kong Gateway the free open-source gateway lacks the analytics, portals, and support of the paid Konnect tiers.; Swagger UI only as good as the specification: a thin OpenAPI file produces thin documentation
  • They diverge on capability: Kong Gateway covers API request routing, Swagger UI covers OpenAPI rendering.
  • Prices and features above were last checked on 29 August 2026.

Where they differ

Only the attributes on which Kong Gateway and Swagger UI actually diverge.

Attributes where Kong Gateway and Swagger UI differ
AttributeKong GatewaySwagger UI
Pricing modelfreemiumOpen source, no licence fee
Platformsweb, linux, apiWeb, Self-hosted, Docker
CategoryAPIsDeveloper Tools
Founded2017Unknown

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

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 Kong Gateway

  • API request routing
  • Plugin ecosystem
  • Developer portals
  • AI Gateway
  • Analytics and observability
  • SSO and audit logs

Only in Swagger UI

  • OpenAPI rendering
  • Try it out
  • Schema display
  • Self-hostable

What people use each for

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

Kong Gateway

  • Routing and securing traffic across microservicesnot Swagger UI
  • Publishing internal or external developer portalsnot Swagger UI
  • Managing rate limits and authentication at the API edgenot Swagger UI
  • Gateway-level routing to multiple LLM providersnot Swagger UI

Swagger UI

  • Publishing API documentation that stays in step with the specificationnot Kong Gateway
  • Letting developers try endpoints before writing any client codenot Kong Gateway
  • Internal API discovery across teamsnot Kong Gateway

Where each one falls short

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

Kong Gateway

  • The free open-source gateway lacks the analytics, portals, and support of the paid Konnect tiers.
  • Plus tier caps API requests at 1M/month before incurring per-million overage charges.
  • Enterprise pricing is custom and not published, making budgeting harder without sales contact.
  • Configuration and plugin management can require significant operational expertise to run at scale.

Swagger UI

  • Only as good as the specification: a thin OpenAPI file produces thin documentation
  • Default presentation is dated compared with modern documentation tools
  • Large specifications render slowly and become hard to navigate
  • Try it out against production needs care with authentication and CORS, and is often disabled as a result

Pricing, plan by plan

Kong Gateway

Free
  • Free TrialFree
    • 30-day enterprise functionality trial
    • Unlimited gateways
    • 30-day analytics retention
  • Plus$undefined/month
    • Up to 5 serverless, 2 hybrid, 2 dedicated cloud gateways
    • 1M API requests/month included
    • Up to 2 developer portals
  • Enterprise$undefined/month
    • Unlimited hybrid and dedicated cloud gateways
    • Unlimited developer portals
    • SSO and audit logs

Swagger UI

Free
  • Swagger UIFree
    • Full functionality
    • Commercial use permitted
    • Community support

Which should you pick?

Choose Kong Gateway if

  • You need api request routing.
  • You want to start without paying.
  • You work on web, linux, api.
  • You also want plugin ecosystem.
Kong Gateway review

Choose Swagger UI if

  • You need openapi rendering.
  • You want to start without paying.
  • You work on Web, Self-hosted, Docker.
  • You also want try it out.
Swagger UI review

Questions people ask

Is Kong Gateway or Swagger UI better?
Neither clearly leads. Kong Gateway starts at Free and Swagger UI at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Kong Gateway or Swagger UI?
Kong Gateway starts at Free and Swagger UI at Free.
Does Kong Gateway or Swagger UI run on more platforms?
Kong Gateway runs on web, linux, api. Swagger UI runs on Web, Self-hosted, Docker.
Can I use Kong Gateway for free?
Both have a free tier, so you can try either at no cost before committing.
What is Kong Gateway best used for?
Kong Gateway is most often used for routing and securing traffic across microservices, publishing internal or external developer portals, managing rate limits and authentication at the api edge, gateway-level routing to multiple llm providers. Of those, routing and securing traffic across microservices and publishing internal or external developer portals are not what Swagger UI is typically brought in for.
What can Kong Gateway do that Swagger UI cannot?
Kong Gateway covers API request routing, Plugin ecosystem, Developer portals, AI Gateway. Swagger UI covers OpenAPI rendering, Try it out, Schema display, Self-hostable.

Answered from the vendors’ own pages

Kong Gateway: Is Kong Gateway free?

Kong's core gateway is open source and free to self-host. Kong Konnect, the managed cloud platform, offers a 30-day free trial before moving to paid Plus or custom Enterprise pricing.

Source
Swagger UI: Is Swagger UI free?

Yes, open source under the Apache 2.0 licence. SmartBear sells commercial SwaggerHub separately.

Kong Gateway: How is usage metered on the Plus plan?

The Plus plan includes 1M API requests per month, with additional usage billed at $200 per extra 1 million requests up to a 10M/month cap, plus per-gateway and per-LLM-model charges.

Source
Swagger UI: What is the difference between Swagger and OpenAPI?

OpenAPI is the specification format; Swagger is the toolset around it, including Swagger UI. The specification was renamed from Swagger to OpenAPI in 2016.

Kong Gateway: What support is included?

Plus includes email support with a 2-business-day SLA, while Enterprise adds dedicated success managers and professional services.

Source
Swagger UI: Can Swagger UI make real API calls?

Yes, through its try-it-out control, though authentication and CORS configuration often mean it is disabled for production APIs.

Share

Related pages

More on Kong Gateway

More on Swagger UI

Keep looking

Other head to heads