Q: how do i make sue a link is safe before i click on it

Some tips from Apple:

Safety tips for handling email attachments and content downloaded from the Internet - Apple Support

Identifying fraudulent "phishing" email - Apple Support

See section on hovering over the link in an email.

It will not cover you in 100% of cases but it's a start.

Some general articles

https://www.security-audit.com/how-to-check-a-link-is-safe-before-clicking-on-it /

http://www.komando.com/columns/349664/dont-click-any-email-link-or-web-link-befo re-asking-these-questions/all

https://www.itap.purdue.edu/newsroom/news/131025_phishing_attempts.html

That depends on what you mean by "safe."

Currently there is no known way for malicious software to be installed merely by visiting a web page. Nevertheless, if the Java web plugin from Oracle is installed, you should disable it.

If you're concerned that the link may lead to something unpleasant, embarrassing, or incriminating, there is no way to rule that out. You would have to trust your friend, and you'd also have to be sure that the message really came from him or her, rather than an impersonator.

Don't click any advertisement. Do not pass your mouse pointer over green or blue, double-underlined text. In Safari's View menu, select Show Status Bar. When you roll over a link, a panel will appear along the bottom of Safari showing you the web address. If you have never heard of the site, then don't click on it.

When I visit a website, my mouse pointer is positioned on the top, or edge of Safari so that it does not come close to any web content when it appears. Never, ever click on any dialog box that appears on your browser over a website, or in a new pop-up. Apple will never pop-up a dialog telling you that you are infected by something. Those are scams with Apple sounding names, or domain names.

Some of these scams will not let you quit Safari until you click on their dialog. Don't. Press option+command+Esc key combination and force quit Safari. Press and hold the shift key when starting Safari again to avoid loading the previous site. From the Safari Application menu, choose Clear History… and remove everything. You might consider enabling the Safari Developer menu item from Safari Preferences : Advanced tab. Once you do this, an option+command+E key sequence will clear your browser cache, since the Clear History process appears to not do so.

A friend sending you a link does mean that it is a safe destination.