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HTTP based ad blocker for Mac OS X

No hacks, no instability
Upgrade Safari whenever you like, no need to wait for an upgraded hack

GlimmerBlocker is no longer maintained and should no longer be used as web sites have migrated from using plain http to using https (i.e. encrypted) which prohibits modification by a proxy unless you resort to install custom SSL certiticates on the client.

You should use a browser extension instead.

It was made as a hobby project during 2007-2008 by Peter Speck. It features both a custom http server and http client and a Mac OS X control panel.

GlimmerBlocker did not only block requests but also allowed for adding custom css and javascript to the pages. It also allowed for modification of the page html before the browser receives the html, which made some modifications much easier than DOM based modifications.

More advanced filtering.

GlimmerBlocker now supports modifying the request before it is sent to the web-server.

A request-modification filter rule can:

  1. Shortcut the request-processing by returning a html/text response directly to the browser. The remote web-server is not contacted at all. This is useful for automatically closing popups and pop-behinds by just returning a simpl html page with a javascript that closes the window.
  2. Return a redirect response, or any other http statuses. Useful for automatically redirecting to print-friendly pages when you don't like sites cutting articles into a zillion small pages.
  3. Fetch a completely different URL.
  4. Modifying cache headers, or the user-agent header.
  5. Use a different http/socks-proxy or dns-server. As this is implemented at the rule leve (in addition to the global settings), you can make it use a different dns-server or http/socks-proxy for that particular URL or site. This means that you can e.g. use OpenDNS for some sites, local dns for some other sites, and ISP-provided dns for the remaining sites. Or you can tell it to use http proxy for those sites.

Useful links:

Request/response flow. Request modification. Object reference.

Dynamic proxy and dns configuration

You can make GlimmerBlocker use a different proxy depending on the Network location, AirPort network name, IP-addresses, interface state, and more. See the proxies documentation.

Socks5 proxies are now supported in addition to http proxies.

Snow Leopard

Important fix: GlimmerBlocker now supports POSTs and PUTs using content-type=chunked for the request data. This is required for saving files on iDisk (previously uploading failed, or created empty files). Reported by Andreas Maks.

The System Preferences panel can now open without requiring System Preferences to relaunch as the Panel now includes a 64-bit version.


You can now copy/paste rules from the 'Filter' tab pane, and drag them into/from other apps.

Rule criterias are extended with path/query 'does not contain', 'not matches regexp' and 'not is'. Suggested by Audun Wilhelmsen.

Better compatibility with ICY clients that expect icy http-headers to be all-lowercase.

Improved checks and reports for broken installations of GlimmerBlocker.

Version 1.4 was released 2009-08-22. List of release notes.