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 v1.4.1 (stable)

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

ZIP : sha256 = 7cf557d4fc25409d47b1855dbafee3be6a9744cecc4fe17c080b92049d087dd1

TAR : sha256 = ac6ad1181769fe7cb256f52f197bcd8fec179b865f4797163a789e78b1aa6a93


Embedded HTTP API Simulator v1.4.1 (stable)

JAR : sha256 = b2d7c4958287441342c61eb7747a3413e26dbb5ca3fcbf57e92249415e88a3c3


Click here for the documentation.


Happy API Simulating!