The API Simulatorâ„¢ downloads contain the full set of features for each edition. There are no limits on hosts/servers, environments, number of simulations, internal users, concurrent network connections, CPUs, CPU cores, virtual vs. physical, cloud or on premise, etc.

Fully functional and free forever – download your copy below.



Standalone HTTP API Simulator v1.5-RC3 (release candidate)

Choose and download the file for your platform (Mac users – choose the ZIP):

ZIP : sha256 = 4e30c6b77b48ed7d884a0e2e8c3dc484ae1ff3cc0d6fe9c90fde09fd7bda44b6

TAR : sha256 = a6b8bac56b353480abbd80fb8870ec7cfbf21c6bbecb91ab63d0371fe2831dcd

This release candidate improves the newly introduced support for HTTP/2.

HTTP/2 implementation detals:

  • Auto-detection of the HTTP protocol – HTTP/1.x or HTTP/2. No additional startup arguments required!
  • Support for HTTP/1.x and HTTP/2 requests on the same port number.
  • Support for HTTP and HTTPS on the same port number for HTTP/1.x and HTTP/2 requests.
  • Support for cleartext (“http” URIs) upgrade from HTTP/1.1 to HTTP/2.
  • Support for starting HTTP/2 for “https” URIs with the TLS Application-Layer Protocol Negotiation (ALPN) extension.
  • Support for starting HTTP/2 with “prior knowledge”.


  • The size in the Access Log is always 0 (zero) for HTTP/2 responses.
  • Request forwarding over HTTP/2 isn’t currently supported.
  • API Recorder only works with HTTP/1.x.


Additional changes and fixes:

  • Added support for case-insensitive URI pattern matching through “matchesIgnoreCase”.
- where: uriPathPattern
  matchesIgnoreCase: <uri-path-pattern>


We would love to hear your feedback – contact us via email at [feedback at]. Many thanks for your interest and support!


Standalone HTTP API Simulator v1.4.2 (stable)

Choose and download the file for your platform (Mac users – choose the ZIP):

ZIP : sha256 = 6dfc9b418d3ee0ec2ed1e7294d30d83d68df70749e1a2abd784244d242aef0be

TAR : sha256 = 50d7d227fd9244b513a9ea6c8b573f40aac1f820f2350f40a0f4cebeed4bab0e


Embedded HTTP API Simulator v1.4.2 (stable)

JAR : sha256 = c8d532858cfa8d346d1c38773f0422dac1cd644284453edd9580011351301c24


Click here for the documentation.


Happy API Simulating!