Browser Advice for NCBI Web Pages

We are sorry, but NCBI web applications do not support Heritrix 3.1, and may not function properly. Please see the table below to find and download a supported browser.
Windows Mac OSX Linux
Internet Explorer8 or greaterThis version of internet explorer on windows operting system is supported by NCBI web applications.This version of internet explorer on mac operting system is not supported by NCBI web applications.This version of internet explorer on linux operting system is not supported by NCBI web applications.
Internet Explorer7This version of internet explorer on windows operting system is not supported by NCBI web applications.This version of internet explorer on mac operting system is not supported by NCBI web applications.This version of internet explorer on linux operting system is not supported by NCBI web applications.
Firefox4 or greaterThis version of firefox on windows operting system is supported by NCBI web applications.This version of firefox on mac operting system is supported by NCBI web applications.This version of firefox on linux operting system is supported by NCBI web applications.
Firefox3This version of firefox on windows operting system is not supported by NCBI web applications.This version of firefox on mac operting system is not supported by NCBI web applications.This version of firefox on linux operting system is not supported by NCBI web applications.
Safari3 or greaterThis version of safari on windows operting system is supported by NCBI web applications.This version of safari on mac operting system is supported by NCBI web applications.This version of safari on linux operting system is not supported by NCBI web applications.
Opera7 or greaterThis version of opera on windows operting system is supported by NCBI web applications.This version of opera on mac operting system is supported by NCBI web applications.This version of opera on linux operting system is supported by NCBI web applications.
Google Chrome5 or greaterThis version of google chrome on windows operting system is supported by NCBI web applications.This version of google chrome on mac operting system is supported by NCBI web applications.This version of google chrome on linux operting system is supported by NCBI web applications.

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Enable Cookies

A "cookie" is information stored by a Web site server (e.g., PubMed) on your computer. See the NLM Privacy Policy for additional information.

In the case of PubMed, it is information about your interactions that may be needed later to perform a function. Cookies allow PubMed to provide more interactive features such as Preview/Index, Clipboard, History, My NCBI and paging through results. Cookies placed by PubMed are removed from your computer after a set time period unless you choose to use a persistent cookie with the My NCBI automatic sign in function.

To use these interactive features you need to enable cookies on your computer. Please consult your browser's Help for information on enabling cookies. If you have problems using cookie-dependent features of PubMed even after enabling cookies, possible reasons may include:

  • Cookies are blocked by your provider or institution. Check with your Internet provider and/or the system administrator at your institution to see if cookies can be accepted. Even if you have them enabled in your Web browser, if they are blocked by your provider or institution (e.g., by a firewall, proxy server, etc.), cookie-dependent features of PubMed won't work.
  • Your computer's date and time settings are incorrect. Check your computer's time settings to ensure that they are correct.

About NCBI Accesskeys

NCBI has enabled the use of accesskeys for easier keyboard navigation of common links and page elements within our pages and our site. Because browsers implement accesskeys differently, even on different operating systems, we have also provided a list of browser accesskeys and actions.

List of NCBI Accesskeys

Accesskey + 1
The NCBI Homepage
Accesskey + 2
The My NCBI Homepage (Sign In page when signed out)
Accesskey + 3
The main content of the current page.
Accesskey + 4
The main site navigation on the current page.
Accesskey + 0
A link to this page.

List of Accesskeys for browsers and operating systems.

  • Microsoft Internet Explorer:
    Alt key + accesskey will focus on a link. You must press the enter key to activate the link.
  • Mozilla Firefox, versions 2 and 3, Microsoft Windows:
    Alt key + Shift + accesskey.
  • Mozilla Firefox, versions 2 and 3, Macintosh:
    Control + accesskey.
  • Safari:
    Control + option + accesskey.
  • Opera:
    Shift + Esc (enabling a menu), followed by the accesskey.

Resolving Page Expired Error Message in PubMed

NCBI is using HTTP1.1 compression/content encoding with Entrez databases (e.g., PubMed). Data compression allows data to be sent faster - a big help for users who have slower connections.

Most recent versions of popular browsers are by default enabled to use HTTP1.1. If, however, users see the message, "Warning: Page has Expired," after using the back button in their browser, they should enable HTTP1.1 compression in their browser. The steps to enable HTTP1.1 compression in Microsoft Internet Explorer (Internet Explorer) are:

  1. From the Tools menu, select Internet Options.
  2. Click the Advanced Tab.
  3. Scroll down to HTTP1.1 settings.
  4. Check the following checkboxes: Use HTTP1.1 and Use HTTP1.1 via proxy connections.
  5. Click OK.
  6. Close MSInternet Explorer and re-open it.

If, after enabling HTTP1.1 compression (be sure to close and re-launch the browser), users still see the "Warning: Page has Expired" message, it is possible that another application is responsible. For example, we have determined that, even with HTTP1.1 compression enabled, Symantec's firewall program, Norton Internet Security can cause the browser to display the error message if the firewall is configured to monitor HTTP connections, which is the default configuration.

If, in the case of a firewall program, users wish to disable HTTP monitoring, they should fully understand the consequences of doing so. We suggest users either consult the product documentation or contact the vendor.