Your one-stop shop for sending and monitoring
RESTful, Streaming, GraphQL, and gRPC API requests

Swell is a API development tool that enables developers to test endpoints served over streaming technologies including Server-Sent Events (SSE), WebSockets, HTTP2, gRPC, and GraphQL.

WebSockets (WS)

Connect directly to WebSocket servers with upgraded HTTP/HTTPS protocols and send messages to test real-time responsiveness

Server-Sent Events (SSE)

Connect to SSEs and watch streaming events come in one by one


Test all three GraphQL root types (query, mutation, subscription) with and without variables


Swell supports full HTTP2 multiplexing of requests and responses. HTTP requests to the same host will be sent over the same connection. Swell will attempt HTTP2 for all HTTPS requests by default, but will revert to HTTP1.1 for legacy servers

New to version 0.4.0!

Swell includes full support for all four streaming types of gRPC - unary, client stream, server stream, and bidirectional stream


Just as Swell can test streaming and non-RESTful APIs, Swell can also test your RESTful APIs


Keep track of your endpoints with collections, and easily import/export groups of requests

Meet the team

Kyle Combs


Jason Ou


Anthony Terruso


Brandon Marrero


Kwadwo Asamoah


Abby Chao


Amanda Flink


Kajol Thapa


Billy Tran


Paul Rhee


Sam Parsons


Yoon Choi


Nancy Dao


Evan Grobar


Dan Stein


Amruth Uppaluri