Not really no.

You could run it in another account on your OS or in a Virtual Machine. But those are not Firefox specific solutions.

If you are deliberately testing dangerous sites you probably need to discuss that on some specialist forum.

Firefox does have

• Very rudimentary phishing and malware protection built in
  How does built-in Phishing and Malware Protection work?
• Again rudimentary Mixed content blocking in Firefox

There is also an experimental multi process mode in pre release versions but that is not intended to protect you from malicious activity.

You may be interested in https://blog.mozilla.org/security/ And for other readers of this thread basic advice How to stay safe on the web

because i see Google Chrome has sandbox mode, so i like to be it in my favorite browser Firefox. i suggest who wants more security in Firefox, try NoScript extension.

John99, Please open this page: https://wiki.mozilla.org/Electrolysis

read 'People' paragraph

'Sandboxing: Bob Owen (bug 925570)'

what is this?

The word Electrolysis often abbreviated as E10s is the multi process system I mentioned.

It is experimental and not completed. That bug is one of a maze of related bugs that track the work done and in progress. That has made it as far as the Developer Edition, but in this instance that does not mean it will go to the Release in two weeks time.

I normally use DE as my default browser. E10s is now enabled by default on DE. That is handy in that I can sometimes crash an individual tab, and restart it without affecting the browser or other Firefox windows or tabs. There are however multiple issues including the fact that many Addons are not compatible with E10s

See

• Please do not post in bugs etiquette but feel free register and follow bugs by CC ing yourelf, or just view and bookmark them.
  • Bug 925570 - Tracking: Process sandboxing work
• DE download https://www.mozilla.org/firefox/channel/#developer

Firefox has a sandbox for some plugins like Flash, and it has a sandbox for media decoding plugins and DRM plugins. These are all enabled by default.

There is work ongoing to provide a sandbox for web content. This has a release with e10s capability (see other replies) as a prerequisite. Currently, that sandbox is available in Firefox Nightly releases. It should be noted that the sandbox is still in development, and although it will stop some unsophisticated attackers ("script kiddies") already, we will continue developing it for the following year(s) to protect against more sophisticated attackers.

There is a wiki page about sandboxing, but it is likely not very accessible without the right technical background: https://wiki.mozilla.org/Security/Sandbox