# How to Use a Proxy Only for Certain Sites in Chrome | ProxyJam

Chrome has one proxy setting for every site. To use a proxy for specific sites only, give it a PAC script: through the system, at launch, or from an extension.

- Canonical: https://proxyjam.com/blog/chrome-proxy-for-specific-sites/
- Updated: 2026-10-08
- Language: en

Chrome on the desktop has no setting that applies a proxy to specific sites. It runs one proxy configuration for all browsing, taken from the operating system, a launch flag, an administrator's policy or an extension. To send only some sites through a proxy, Chrome needs a PAC script, a short function that picks a proxy for each request, which you write yourself or an extension builds from rules.


## Confirm which route a site took

1. **Put a check page on the list for a minute** Add proxyjam.com to the sites your script or rules send through the proxy, next to the sites you care about.
2. **Open the check page** [What Is My IP](/what-is-my-ip/) shows the address that reached it and the internet provider and network (ASN) that address belongs to. Both should be the proxy's.
3. **Take it off the list and reload** The page should now show your own connection. With both readings as expected, listed sites go through the proxy and the rest go direct.

## Where the routing comes from, and what each way affects

|  | System proxy settings | A separate Chrome instance | A proxy extension |
|---|---|---|---|
| What it affects | Every application on the computer that reads system settings | Only the windows of that instance | The Chrome profile the extension is installed in |
| How sites are chosen | By a PAC script hosted at a URL | By which window you open a site in | By rules the extension turns into a PAC script |
| Changing the setup | Edit the hosted script | Quit and relaunch with new flags | Edit a rule in the extension |
| A proxy that needs a password | Chrome asks in a dialog | Chrome asks in a dialog | The extension can answer for HTTP and HTTPS proxies |

Scope comes from Chromium's documentation of where proxy settings are read and from the flags' own descriptions; the rest follows from how each method is set up. We ran no speed or reliability measurements. Wherever a PAC script decides the route, Chrome passes it an HTTPS address as scheme, host and port only.


## Quick answers

### Does Chrome's bypass list do the same thing?

It does the reverse. The --proxy-bypass-list flag names hosts that skip the proxy, and it only takes effect together with --proxy-server, so everything not on the list goes through the proxy. To proxy a short list of sites and leave the rest direct, use a PAC script.

### Do incognito windows use the same proxy?

Yes, by default. Chrome's proxy API documentation says incognito windows inherit the settings of regular windows, and an extension can set a separate value for incognito when it needs one.

### Why does Chrome say it is using proxy settings from an extension?

An extension has set the proxy, and Chrome lets an extension or an administrator's policy determine the setting in place of the system one. Disable the extension, or switch it to direct, to hand control back.

### What happens to sites that match no rule?

They get whatever the script returns last. In the example script that is DIRECT, so unmatched sites connect without a proxy. ProxyJam Connector calls this the fallback and sets it to Direct until you choose otherwise.


## Sources

- [Chromium: proxy support notes (proxy.md)](https://chromium.googlesource.com/chromium/src/+/HEAD/net/docs/proxy.md), where Chrome reads proxy settings from, and that PAC scripts receive HTTPS addresses without path or query since Chrome 52
- [Chromium: settings strings](https://chromium.googlesource.com/chromium/src/+/HEAD/chrome/app/settings_strings.grdp), the "Open your computer's proxy settings" entry, described as opening settings that apply to the entire computer
- [Chromium: network settings](https://www.chromium.org/developers/design-documents/network-settings/), the `--proxy-server`, `--proxy-bypass-list` and `--proxy-pac-url` flags
- [Chromium: user data directory](https://chromium.googlesource.com/chromium/src/+/HEAD/docs/user_data_dir.md), the `--user-data-dir` flag, and that two running instances cannot share one directory
- [Chrome for Developers: chrome.proxy API](https://developer.chrome.com/docs/extensions/reference/api/proxy), the proxy modes an extension can set, and incognito windows inheriting the regular setting
- [Chrome for Developers: chrome.types API](https://developer.chrome.com/docs/extensions/reference/api/types), the scopes a setting can be stored in, including incognito-only ones
- [MDN: Proxy Auto-Configuration (PAC) file](https://developer.mozilla.org/en-US/docs/Web/HTTP/Guides/Proxy_servers_and_tunneling/Proxy_Auto-Configuration_PAC_file), the FindProxyForURL function, its return values and dnsDomainIs
- [Microsoft Support: Use a proxy server in Windows](https://support.microsoft.com/en-us/windows/experience/connectivity-networking/use-a-proxy-server-in-windows), pointing Windows at a proxy setup script
- [RFC 5737: IPv4 Address Blocks Reserved for Documentation](https://www.rfc-editor.org/rfc/rfc5737.html), the 203.0.113.0/24 range used for the example proxy address




To use a proxy for specific sites in Chrome, you give the browser a PAC script
that names the sites, and Chrome consults it on every request. There are three
places the script can come from: your operating system, a separately launched
Chrome, or an extension.

## Does Chrome have a per-site proxy setting?

No. Chrome's settings page has a single proxy entry, labelled "Open your
computer's proxy settings", and Chromium describes those settings as applying to
the entire computer
([Chromium's settings strings](https://chromium.googlesource.com/chromium/src/+/HEAD/chrome/app/settings_strings.grdp)).

[Chromium's proxy notes](https://chromium.googlesource.com/chromium/src/+/HEAD/net/docs/proxy.md)
list four places Chrome can take its proxy configuration from: an
administrator's policy, command-line flags, an extension, and the operating
system. Whichever one is in force supplies one configuration for everything
the browser loads, and a per-site decision lives inside that configuration as a
PAC script.

## What does a PAC script do?

A PAC (proxy auto-configuration) script is a JavaScript function named
`FindProxyForURL`. Chrome calls it for each request with the address and the
host name, and uses the string it returns: `DIRECT` for no proxy, or
`PROXY host:port` for a proxy server, as
[MDN's PAC reference](https://developer.mozilla.org/en-US/docs/Web/HTTP/Guides/Proxy_servers_and_tunneling/Proxy_Auto-Configuration_PAC_file)
documents.

This script sends one domain and its subdomains through a proxy and everything
else direct. The proxy address comes from a range reserved for documentation
([RFC 5737](https://www.rfc-editor.org/rfc/rfc5737.html)); put your own in its
place.

```javascript
function FindProxyForURL(url, host) {
  if (host === "example.com" || dnsDomainIs(host, ".example.com")) {
    return "PROXY 203.0.113.10:8080";
  }
  return "DIRECT";
}
```

Add one condition per site you want proxied. The final `return` decides what
happens to every site that is not listed.

## Which ways can I give Chrome a PAC script?

Three: through the system proxy settings, through a separately launched Chrome,
or through an extension. They differ in how much of the computer they touch and
in how a change takes effect.

### Through the system proxy settings

On Windows, the proxy settings have a "setup script" option that takes the
script's address, as
[Microsoft's guide](https://support.microsoft.com/en-us/windows/experience/connectivity-networking/use-a-proxy-server-in-windows)
shows, and Chrome follows the system setting. The script has to be reachable at
a URL. Every application that reads the system proxy settings will use it as
well, so this suits a script you mean for the whole machine.

### In a separate Chrome instance

Chrome accepts proxy flags at launch, listed on
[Chromium's network settings page](https://www.chromium.org/developers/design-documents/network-settings/):
`--proxy-server` names one proxy, `--proxy-bypass-list` names hosts that skip
it, and `--proxy-pac-url` points at a script. Launched with its own
`--user-data-dir`, the second Chrome runs next to your usual one, since two
running instances cannot share a data directory
([Chromium's notes on the user data directory](https://chromium.googlesource.com/chromium/src/+/HEAD/docs/user_data_dir.md)).

```sh
google-chrome --user-data-dir="$HOME/chrome-proxied" --proxy-server="http://203.0.113.10:8080"
```

That instance sends all of its traffic through the proxy, so the window you
open a site in decides its route. Changing the proxy means quitting the
instance and launching it again with new flags.

### With a proxy extension

An extension sets Chrome's proxy for the profile it is installed in, through
the [chrome.proxy API](https://developer.chrome.com/docs/extensions/reference/api/proxy),
and a switcher with rules compiles them into a PAC script. Our free
[ProxyJam Connector](/browser-extension/) works this way, in Chrome and in
Microsoft Edge:

1. Add a profile with the proxy's host, port and protocol.
2. Add a rule, for example "Domain + subdomains" with `example.com`, pointing at
   that profile. The first rule that matches a site wins.
3. Leave the fallback on Direct so that sites matching no rule connect without a
   proxy.
4. Choose Auto in the toolbar popup.

For a matched site, Connector's script names that one proxy with no direct
option after it. If the proxy is down, the site fails to load and your own
address is never used for it.

## Can each tab use a different proxy?

Not in Chrome. The [chrome.proxy API](https://developer.chrome.com/docs/extensions/reference/api/proxy)
stores one value for a profile and takes no tab as a parameter, so a tab has
nothing of its own to set.

The workable unit is a profile or an instance. Create a second Chrome profile
for the proxied work and install the extension there, or launch a second
instance with its own flags, and keep the two windows side by side. Each window
then carries its own proxy.

## Why does a rule with a path fail on HTTPS sites?

Chrome gives a PAC script only the scheme, host and port of an `https://`
address. The path, query and fragment have been stripped since Chrome 52, and
the option that turned this off was removed in Chrome 75
([Chromium's proxy notes](https://chromium.googlesource.com/chromium/src/+/HEAD/net/docs/proxy.md)).

A rule like `example.com/shop/*` therefore matches no HTTPS page. Write rules on
the host name, and give a section of a site its own subdomain if it needs its
own route. Plain `http://` addresses still reach the script with their path,
although Chromium advises against relying on that. Connector shows a warning
next to any rule that depends on the path.

## Which way should you choose?

For a few sites and one proxy, an extension is the least work, and the
[extension page](/browser-extension/) lists what Connector can and cannot do on
Chrome. A proxy that asks for a password is covered in
[why Chrome keeps asking for a proxy username and password](/blog/chrome-proxy-password-prompt/),
and moving rules over from an older switcher in
[what changed under Manifest V3](/blog/switchyomega-manifest-v3/).

If the proxy you route those sites through should keep one address registered
to an internet provider, that is [what an ISP proxy is](/blog/what-are-isp-proxies/).
ProxyJam sells static residential (ISP) proxies on the
[ISP proxies page](/isp-proxies/), with prices on the [pricing page](/pricing/).