hubcap throttle

Simulate slow network conditions using a throttling preset.

When to use

Simulate slow network conditions to test how a page performs under constrained bandwidth and high latency. Use offline to fully disconnect the browser from the network. Use block to block specific URLs rather than slowing all traffic.

Usage

hubcap throttle <preset> | --disable

Arguments

Argument	Type	Required	Description
`preset`	string	Yes (when not disabling)	Throttling profile to apply (e.g. `3g`, `slow3g`, `fast3g`, `4g`, `wifi`)

Flags

Flag	Type	Default	Description
`--disable`	bool	`false`	Disable network throttling and restore normal speed

Output

Field	Type	Description
`preset`	string	Name of the applied preset (when enabling)
`enabled`	boolean	Whether throttling is active (when enabling)
`disabled`	boolean	Whether throttling was disabled (when disabling)

When a preset is applied:

{"preset":"3g","enabled":true}

When disabled:

{"disabled":true}

Errors

Condition	Exit code	Stderr
Unknown preset name	1	`error: unknown preset "name"`
Chrome not connected	2	`error: connecting to Chrome: ...`
Timeout	3	`error: timeout`

Examples

Simulate a 3G connection:

hubcap throttle 3g

Simulate a slow 3G connection:

hubcap throttle slow3g

Disable throttling:

hubcap throttle --disable

Throttle the network, load a page, and capture performance metrics:

hubcap throttle slow3g && hubcap goto https://example.com && hubcap metrics