AWS · Free tool

AWS API Gateway cost calculator

REST API and HTTP API look similar in the console. The bills do not. Plug in your traffic, see all three flavors side by side, and see the dollar number on a HTTP API migration.

Side-by-side monthly cost

Flavor	Monthly	Detail
REST API	$0	$3.50 / 1M (tiered)
HTTP API	$0	$1.00 / 1M (tiered, payload-aware)
WebSocket API	$0	$1.00 / 1M msgs + $0.25 / 1M conn-min

REST -> HTTP API migration value

Monthly saving	$0
Annual saving	$0
Discount rate	0%

Where API Gateway bills sneak up on teams: REST APIs left in production from the early-2020 default, WebSocket clients that never disconnect, HTTP API charging extra 512 KB chunks, CloudWatch Logs from API Gateway access logs, and Route 53 charges from custom domain resolutions.

REST or HTTP, pick once and stop paying for both

AWS launched HTTP API in 2020 as the modern, slimmer successor to REST API. The discount has been 71 percent on requests since day one, and most teams who started before 2020 are still on REST because the migration was never urgent enough.

For a 100M-request-per-month API, the monthly difference is around $250. For 1B requests, it is $2,500. Multiplied by the number of stages and accounts most teams run, this is the cleanest savings line in the AWS catalog.

Frequently asked

How is API Gateway priced exactly?

Three flavors with different rates. REST API charges $3.50 per million requests for the first 333 million per month, dropping in tiers. HTTP API charges $1.00 per million requests, a 71 percent discount on REST. WebSocket API charges $1.00 per million messages plus $0.25 per million connection-minutes. Data transfer charges apply on top.
Why is HTTP API so much cheaper than REST API?

HTTP API is a slimmer service. It dropped some REST features that most production teams never use: usage plans and API keys, request validation, request transformation, and AWS WAF native integration (you can still attach WAF in front of an HTTP API). Most teams who reach for those features can replicate them at the application layer or in front of HTTP API. The 71 percent saving is real for almost any new API.
When should I stay on REST API?

Two reasons. One, you depend on private REST APIs in a VPC behind PrivateLink (HTTP API supports private endpoints differently). Two, you have a Cognito User Pool with REST-API-specific features like API key throttling and usage plans the team uses for monetization. For everything else, HTTP API is the modern default.
What about WebSocket API pricing surprises?

WebSocket bills two dimensions: messages and connection-minutes. Long-lived connections at $0.25 per million minutes look harmless until you have 50,000 concurrent connections for 30 days, which is 50,000 x 60 x 24 x 30 = 2.16 billion connection-minutes, or $540 a month before any messages flow. Disconnect idle clients aggressively and use one connection for many message types.