A proxy manager does not supply IP addresses. It organises the ones you already have, so each tool does not need its own copy of every host, port and password. They come in a few shapes:
- Browser extensions such as ZeroOmega and FoxyProxy switch proxies by site or by profile.
- System-level tools such as Proxifier send chosen applications through chosen proxies, including apps with no proxy setting of their own.
- Local proxy servers run on your machine or network, accept connections on one address, and forward each request to an upstream proxy from a list, with rules, rotation and retries.
- Code-level middleware, such as a rotating middleware in Scrapy, does the same job inside a crawler.
Why use one
- One place to keep credentials, rather than in every script.
- Per-domain rules: a static IP for the site where you log in, a rotating pool for everything else.
- Health checks that take a failing proxy out of rotation.
- A single local endpoint for tools that cannot authenticate, forwarding to a proxy that requires credentials.
What to watch
A local manager adds a hop, so it adds a little latency. A hosted or third-party manager sees your proxy credentials and your traffic, so treat it like any other vendor with access to both. And the rules are only as good as your testing: check which exit a request uses with an IP echo service before you trust the configuration.
Rolling your own
For a scraper, a list of proxies and a small rotation function is often all the manager you need. How to rotate proxies in Python builds one with health checks.