Only current Caltech students, faculty and staff have remote-access privileges to Caltech-licensed library resources.

Obtain an up-to-date access.caltech account.

Use links on the library web pages.

Links on the library web pages (including links found in the library catalog and those on the Find E-Journals page) are proxied. When clicking on a proxied link for the first time in the session, remote users are prompted for their access.caltech username and password. One successful login establishes access to most Caltech-licensed resources.

(Optional): Establish a VPN Account.

  • Information about VPN accounts and installation of VPN software.
  • You must use the “Caltech-Tunnel All” option.
  • VPN slows down connections to all IP addresses. For most library resources, proxied links are the preferred method.

(Optional): Use the Caltech Library Proxy bookmarklet.

The Caltech Library Proxy bookmarklet lets you easily reload the current page via the library proxy to see if we have access. Works with any browser.

Install the bookmarklet

For most browsers, simply drag this link, Caltech Library Proxy, to your Bookmarks or Favorites toolbar.

For Internet Explorer and Firefox, you can also right-click on the link and select "Bookmark This Link" (Internet Explorer) or "Add to Favorites" (Firefox).  Internet Explorer might prompt you with a warning "You are adding a favorite that might not be safe.  Do you want to continue?".  Click "Yes" to continue.

For iPad or iPhone

Prepare your iPad & open this tutorial in mobile Safari

  • From your iPad, go to “Settings” and tap on “Safari.” Set Show Favorites Bar to “ON.” Under Advanced set JavaScript to “ON.” 
  • Next, open the Safari app and open this current page (
  • Now copy the code in the section below (Proxy bookmarklet code)

Proxy bookmarklet code

To copy the code below — press and hold on the code and then release; then adjust the blue overlay so it covers the entire code, and tap “Copy.”


Create a temporary bookmark in mobile Safari

Next, tap on the share icon (square with an arrow) at the top of your Safari page and tap “Bookmark.” Ensure that it will be saving to the “Favorites” and then hit “Save.”

Update the temporary bookmark with the code for the bookmarklet

  1. Now tap on the bookmark icon (open book) to pull up your bookmarks. Tap on the “Favorites” folder. Then tap “Edit” in the bottom corner of your window.
  2. Select the bookmark that you just created. Change the name to something of your choice – perhaps ‘Caltech Library Proxy’ or ‘Proxy’.
  3. Next, erase the URL shown and paste the bookmarklet code for Library Proxy (press and hold, then release, then tap “Paste”).
  4. Hit “Favorites” located in the top left corner to go back. Tap “Done” located in the bottom right corner. Tap the bookmark icon to make it disappear.
  5. If your new bookmark doesn't appear immediately in the Favorites toolbar, close Safari and reopen.

Use the bookmarklet

If you're off-campus and want to view a journal article, you can use the proxy bookmarklet to gain access. Simply browse to the article or database you're interested in, click the bookmarklet and enter your Caltech IMSS username and password.

This will not work for all publishers and vendors, so if the bookmarklet fails to give you access to a journal you know we subscribe to, use the Find E-journals page instead.


  • The bookmarklet will not work if you have javascript disabled in your browser
  • The bookmarklet doesn't work properly with GeoScienceWorld
  • The bookmarklet doesn't work properly with Nature.

(Optional): Install LibX.


LibX Caltech edition is an extension which will let you access the library’s resources directly from your browser. It adds a Caltech Library icon to the upper right corner of your browser with an interface to search the library catalog and will also add a right-mouse context menu to reload the current page using the library’s proxy server (to allow for off-campus access to resources which require a Caltech IP address).

Version 2.0 of LibX is available for Firefox and Chrome, but the Firefox version is running into difficulty with the new way Firefox is verifying extensions. If you're only interested in the proxy support, you might want to use the bookmarklet instead.

(Optional): Configure Google Scholar.

  • If you use Google Scholar, you can configure it to have the Caltech Connect links appear off-campus by changing your Scholar Preferences.
  • Scroll down to the "Library Links" section. Type Caltech in the search box and click on "Find Library". Check the box to the left of "California Institute of Technology - Caltech Connect" and then click the "Save Preferences" button.

(Optional): Configure ADS

  • If you use the Astrophysical Data System, it's worth setting your preferences so that Caltech Connect links appear in your search results. You can do this by signing in to your account at ADS.
  • Select "User Account Update" and then "Library Links Settings". Use the drop down menu to select "California Institute of Technology" as your library link server. Once you've saved your settings, the Caltech Connect button will display in your search results

JPL staff: please contact the JPL Library (library [at] for available options.
Caltech staff at JPL: Our proxy server will not work for you at JPL. You will need to use VPN.

You are a remote user if your IP address falls outside the range 131.215.*.*. This includes Caltech offices at CSO, IPAC, LIGO, OVRO, and Palomar.