I'm currently in a country where internet access is expensive (New Zealand), and I'm curious if I'll be able to download Portal 2. How big is the download in Steam?

  • Don't know about Portal 2, but Civ 5 was an estimated five hours on a 10 Mbit line. Commented Jun 7, 2011 at 21:12
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    This is going to depend on whether or not you already have a source game on your computer (TF2, CS:S, etc - I think Portal 1 but I'm not sure). The Source engine is a substantial size, and if you already have that downloaded for another game you'll save quite a bit of bandwidth. Commented Jun 7, 2011 at 21:15
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    If it can help, you can try to get a friend to copy the content of C:\Program Files (x86)\Steam\steamapps\common\portal 2 on a CD and send it to you via mail. It works.
    – Hilydrow
    Commented Jun 8, 2011 at 7:00
  • Eric, thats a great idea. I may try this, especially if this is the biggest part of the download.
    – leecbaker
    Commented Jun 8, 2011 at 22:53
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    I really feel like this is too localized in time to be answerable. See: gaming.stackexchange.com/questions/61680/…
    – GnomeSlice
    Commented Nov 29, 2012 at 21:26

3 Answers 3


The system requirements list 7.6 GB for Portal 2. If you already have a Source game the size could be much smaller since the Source engine compromises a large part of the download.

  • That's about what I was thinking it would be, but can you provide a source? Commented Jun 7, 2011 at 21:16
  • @Dave As you wish
    – user9983
    Commented Jun 7, 2011 at 21:20
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    There are multiple versions of the steam engine, and the 7.6 gb includes an update to the steam engine, I believe these various engine versions are kept side by side, so the 7.6 gb will apply even if you already have Half Life 2 or L4D.
    – Warren P
    Commented Jun 7, 2011 at 23:28

The amount of data that needs to be downloaded is different than the amount of disk space the game uses once installed. As reported by the installer screen before installing Portal 2 the disk space required during the installation is 11.6GB:

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However once you start the download process, the amount of data required is significantly less at 6.6GB. Additionally, I have tested that this download size is not affected if you already have the Source SDK or other Source based game(s) installed.

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    6.6 GB to download! I think this one is the only right answer, the others are just guessing.
    – Philipp
    Commented Jan 3, 2013 at 9:32
  • The download size does not reflect the size of the game on disc, since the download is heavily compressed.
    – user28015
    Commented Jan 3, 2013 at 12:52

Yeah like all the other have said, Need to have Source SDK Base 2007 installed already, and that file is a whooping 4.8Gigs (if i remember correctly - around 4gig range) So I would say Portal 2 is roughly 2.5 gigs

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