Speeding Up Safari

in Mac Software edited January 2014
From O'Reilly:

Speed up Safari

May. 21, 2004 06:53 AM

This little hack is courtesy of macOSXhints.com and boy oh boy does it work great! The hack comes out of an interesting piece written by the Safari developer David Hyatt on the adding of timers to browsers. Apparently, in order to render obsolete flashing pages that can occurs when a webpage loads, (due to the client getting data from any number of sources; the stylesheet, various data sources, etc) web browsers are programmed with a little delay. The delay is, appropriately, conservative. But by adjusting a variable in the Safari preference file you can speed Safari?s delay time up.

To try this (after backing-up, etc.) go to the terminal after Safari has quit and type:

defaults write com.apple.Safari WebKitInitialTimedLayoutDelay 0.25

The default time in the Safari preference time is 1.0. Now go ahead and launch Safari. Notice a difference? I sure did! As someone commented on macoxhints.com it was like getting a new machine. I wouldn't go that far, that is certainly feels like Safari had a double-shot espresso.

Original MacOSXHints:


This is what looks like the best modification:

defaults write com.apple.Safari WebKitInitialTimedLayoutDelay -float 0.25

Original post:

defaults write not quite right

Authored by: tinb on Thu, May 20 '04 at 04:16AM

Not quite right. You need to specify the "0.25" as a float value, not a string value which is the default. So

defaults write com.apple.Safari WebKitInitialTimedLayoutDelay -float 0.25

will do it right.


To summarize:

You can speed up Safari by decreasing the delay in opening web pages. To do so:

1. Quit Safari

2. Open Terminal

3. Type:

defaults write com.apple.Safari WebKitInitialTimedLayoutDelay -float 0.25

Hit return, close Terminal

4. Restart Safari

The difference is quite noticeable.


  • Reply 1 of 10
    1337_5l4xx0r1337_5l4xx0r Posts: 1,558member
    Dude, that rules! Finally, speed on par w/ mozilla/gecko!
  • Reply 2 of 10
    escherescher Posts: 1,811member
    I just applied this hack and it indeed helps speed the render time in Safari. As far as I can tell, the hack reduces the time Safari waits to render a page when it is still missing content. E.g. sometimes a slow-loading ad banner will hold up the rendering of an entire web page. With the changed setting, pages can render without waiting for slow ads. It's a godsend! Beautiful!

  • Reply 3 of 10
    bspearsbspears Posts: 147member
    Works like a charm

  • Reply 4 of 10
    wrong robotwrong robot Posts: 3,907member

    that's really impressive. It's like the first time I got broadband all over again!
  • Reply 5 of 10
    /\ldie/\ldie Posts: 70member
    Good improvement. Basically safari starts rendering the page earlier, although not all off the data is downloaded yet.
  • Reply 6 of 10
    aquaticaquatic Posts: 5,602member
    Just got 10.3.4. People say Safarin in 10.3.4 is faster. Should we still apply this "trick" to Safari in 10.3.4?
  • Reply 7 of 10
    scottscott Posts: 7,431member
    I guess writing 0.0 would cause problems for something else?
  • Reply 8 of 10

    Originally posted by Aquatic

    Just got 10.3.4. People say Safarin in 10.3.4 is faster. Should we still apply this "trick" to Safari in 10.3.4?

    Yes. One of the developers was talking about changing this in his blog, I assume that's where people got the idea from. But when people asked if the speed up they noticed in 10.3.4 was due to this change he said:


    It's a placebo. The Safari in 10.3.4 contains only a handful of fixes and is no faster than previous versions.

  • Reply 9 of 10
    kelibkelib Posts: 740member
    Nice indeed
  • Reply 10 of 10
    nebagakidnebagakid Posts: 2,692member
    does that mean the content will not load late even after the page is rendered?
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