Q: I have a macbook pro: 2.3 GHz Intel Core i5, 4GB 1333MHz DDR3 Ram. Version 10.7.5. When I open some websites, I get a message that web browser is outdated. I use safari. When I do a software update, It says software is up to date. Please help.

Safari maxes out within a release of OSX.  New version of OSX would be needed for new Safari version.

Firefox is not limited within an OSX and probably has a version that will work.  Chrome may as well but is a resource hog.  Opera is a third option.

When I do a software update, It says software is up to date.

That's because 10.7.5 is the latest update for Lion. You're confusing, "Updates," with "Upgrades."

Software Update doesn't Upgrade your OS X version. You get OS X upgrades by using the App Store app.

Hi roneilfromadelaide , I can see how having an up to date Safari version will be beneficial as many secure websites require it. I my self had to recently upgrade to get the full experience of my banking site. You can you these steps to verify if your eligible for and how to Upgrade OSX Upgrade to OS X El Capitan - Apple Support  in doing so will update you to one of the latest versions of Safari. At which point if still needing a higher version,How to get software updates for your Mac - Apple Support It is highly recommended you have a Time Machine backup or some other type of backup of all personal files.

To summarize:

Safari is tied to OSX versions.  You are at the maximum Lion version, so are at the maximum Safari for Lion.  To get a new Safari, you need to upgrade OSX, which is a big decision in itself, as you must weigh the risks of losing what Lion has and taking on the limitations of the new OSX versions.  <EDIT> Changing to a new OSX is not "automatic" like it is changing the sub-version of Lion ... you must download a new complete OSX version, make a backup of current, install the new OSX intentionally. <EDIT>

Firefox, Chrome, Opera are not tied to OSX versions.  You can install Firefox/Opera/Chrome which gets new releases regularly.  You *could* stay with Lion and still access the websites that complain about needing a newer browser.

• How to download & install Firefox on Mac - Mozilla Firefox Help:

https://support.mozilla.org/en-US/kb/how-download-and-install-firefox-mac

{There also are add-ons + other custom items from the Firefox site}

First, I'd go with the new browser. It is free and sees updates.

And it is less of a dog than Chrome.

Good luck in this matter!