Skip to main content

Import from Charles Proxy

In this guide we will walk through importing traffic from a Charles Proxy Session. These files generally have the .chlz file extension and represent request/response pairs recorded by the proxy.

We'll take the following steps:

  1. Export a Charles Proxy session file (.chlz)
  2. Convert the .chlz file to .har
  3. Import into Speedscale

Export a Charles Proxy Session

Charles Proxy makes it very easy to save proxy results. Open your desired set of traffic and find the Save Session As option or equivalent:

Charles Proxy Import

Note the location of the newly created .chlz file.

Convert to HAR Format

Charles Proxy conveniently provides the ability to convert from its proprietary format into the standard HAR file format used to store browser requests. From the Charles Proxy documentation we want to run a command like the following:

Charles session.chlz ready_for_speedscale.har

Note the location of the newly created .har file.


It's now time to import the HAR file into Speedscale. Remember to select whether you want tests or mocks to be generated. Speedscale has the ability to reverse incoming traffic so that it forms the basis for a service mock. Practically speaking that means you can record traffic from your browser to a backend using Charles Proxy and then have Speedscale mock out the back end services the browser is talking to.

Continue importing the HAR file by following the import from HAR guide.