Install on IIS

mod_pagespeed runs on IIS as a native, in-process module: the successor to IISpeed. Download the signed MSI, run it, iisreset, and the module optimizes every site that has a pagespeed.config. The IIS package ships from the 1.15 packaging channel.

Requirements

• Windows Server 2019 or later (IIS 10 or later)
• 64-bit only
• Visual C++ Redistributable 2022
• The IIS worker process identity needs write access to the cache directory; the installer grants it for the default directory

Install the module

1. Download the IIS MSI installer. Each binary has a .asc signature next to it.
2. Run it on the Windows Server host. The installer registers the module in IIS as a native HTTP module and creates the default cache directory at %ProgramData%\We-Amp\IISWebSpeed\Cache.
3. Run iisreset.

The module reads pagespeed.config: a server-level file at %ProgramData%\We-Amp\PageSpeed\pagespeed.config and, optionally, one in each site’s physical root. The minimal file is two lines:

pagespeed on
pagespeed FileCachePath %ProgramData%\We-Amp\IISWebSpeed\Cache

IIS configuration documents the file format, the lookup order and path matching.

Coming from IISpeed

If IISpeed is installed on this host, uninstall it before running the MSI. The two modules register the same handler in IIS and cannot coexist. Open Apps & features (or Programs and Features), remove “IISpeed”, run iisreset, then run the installer. Migrate from IISpeed walks through the whole move, configuration and cache included.

The optimizer service

The installer also installs the optimizer worker, as the Windows service WeAmpPageSpeedOptimizer under its own virtual account, and leaves it disabled: until you turn it on, the module behaves exactly as it does without it. Turned on and pointed at with the DaemonSocketPath and DaemonVolumePath directives, it takes over in-place optimization: the module records each eligible resource, the optimizer builds optimized variants, and the module serves the variant that fits each client. An upgrade or repair with the installer keeps a service you turned on running and keeps the cache size you chose (OPTIMIZERCACHESIZE, 1 GiB by default).

IIS Express

For local development with IIS Express, add the module to applicationhost.config in %userprofile%\Documents\IISExpress\config\:

1. Copy the module DLL to a known location
2. Add the module registration under <globalModules> and <modules>
3. Restart IIS Express

Verify it works

On IIS the module emits X-Page-Speed, the same header as the nginx module. Check for it with PowerShell:

(Invoke-WebRequest http://localhost/ -Method Head).Headers["X-Page-Speed"]

Then open /pagespeed_global_admin on the server itself. Is it working? has the other checks.

Next steps

• IIS configuration: pagespeed.config, lookup order, path matching and IIS tuning
• Filter selection: choosing and tuning filters
• Admin console: restricting the admin pages
• Migrate from IISpeed