No Caching

No Caching removes the headers that let apps and browsers reuse old responses. With it on, requests go to the server for fresh data and responses tell the app not to store them. Use it when you change something on the server, or in a mock, and want to be sure the app sees the change instead of a cached copy or a 304 Not Modified.

Turn No Caching on

No Caching has no rules. When it’s on, it applies to every request Cloak Proxy can read.

1. Choose Tools › No Caching (the checkmark item), or open Tools › Debugging Tools…, select No Caching and flip its switch to On.

   You can also use the Tools button in the toolbar, or search for Turn On No Caching in Search Everything (⇧ ⌘ A).

2. Make your requests again. Changed requests show a No Caching badge in the traffic list, and No Caching appears in the status bar.

3. Turn it off the same way when you’re done.

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No Caching has a single switch. The page lists what it changes.

1. On/Off switch. No rules to set up.
2. Changes made to requests.
3. Changes made to responses.

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What No Caching changes

Requests

Header	Change
If-None-Match	Removed
If-Modified-Since	Removed
If-Match	Removed
If-Unmodified-Since	Removed
If-Range	Removed
Cache-Control	Set to no-cache, replacing any value the app sent
Pragma	Set to no-cache

Without the conditional headers, the server can’t answer 304 Not Modified and sends the full response.

Responses

Header	Change
ETag	Removed
Last-Modified	Removed
Expires	Removed
Cache-Control	Set to no-store, no-cache, must-revalidate, replacing the server’s value

How No Caching works with other tools

• Request changes are made after Map Local and Mock Sets, so they only affect requests that go to a server.
• Response changes are made to every response, including those from Map Local and Mock Sets, before response scripts and the response breakpoint. A script can set caching headers back if you need it to.

Conditional writes lose their protection

Some APIs use If-Match or If-Unmodified-Since on PUT, PATCH or DELETE to avoid overwriting someone else’s change. No Caching removes those headers too, so the server can’t check them. Turn it off when you test that behavior.

Note

No Caching only changes traffic that goes through Cloak Proxy, and only plain HTTP and HTTPS with SSL Proxying on. If an app already holds a fresh copy in its own cache, it may not send a request at all. Clear the app’s cache once after you turn No Caching on.

Related

Debugging toolsEvery tool and how to turn them on and off.

Insights: performanceFind uncached static files and duplicate requests.

Map LocalServe a local response; No Caching keeps the app from caching it.