How can I set a default zoom level in Safari?
According to this post from Apple's Safari Support discussion forum:


  1) Create a file named defaultzoom.css (or any name you like, just make sure it has a css extension.)
  
  2) Copy and paste in the following:  

    body {  
      zoom: 130%;  
    }

  
  change 130 to whatever number suits you. &gt;100 means zoom in, &lt;100 means zoom out. Don't forget the % percent sign!
  
  3) In safari, go to Preferences &gt; Advanced. Under style sheet, select Other... and point to the file you created.
  
  4) You may need to restart safari for the change to take effect.




[In the above, both the emphasis and code formatting (for non-code-related text) were added to the original quote by Am1rr3zA].