What is the maximum file size I can transfer using HTTP? And using FTP?

Question

Added: I am conducting a study for a new system we're going to develop in my work. It consists in authenticating users, displaying what files they want to download and downloading them. Also, if the files are not readily available, the user can't download them, but the server obtains a copy of the requested file and notifies the user by mail when he can get the file. We expect files to be tipically from 2 to 50 gigabytes in size, for now.

I just want to check if it's possible to write a Web application to solve the problem or if we need to make a client-server solution.

Solution 1

There is no maximum. Any max you are encountering is application specific or site specific.

I've downloaded DVD isos from Microsoft using HTTP and FTP without issue (~4gb).

I've also uploaded huge files via both methods.

Can you elaborate on what you're trying to do?

Solution 2

As already answered, the protocol has no limitations, but most HTTP servers have default upload limits out-of-the-box:

IIS6 uses MaxRequestEntityAllowed (default is 4GB) and AspMaxRequestEntityAllowed (default is 200000 bytes) in metabase.xml.

IIS7 uses maxRequestEntityAllowed: **appcmd set config /section:asp /maxRequestEntityAllowed:***int* (default is 200000 bytes)

Apache uses LimitRequestBody (default is 2GB)

Solution 3

There are no such limitation by-design in protocols you said. Only timeouts on concrete servers

Solution 4

The upload in HTTP is usualy limited as the server has to wait until the (mostly slow) upload is finished to respond to the request.

Solution 5

And one important question - are you going to upload or download?

I could say that downloading has significantly less limitations that uploading. I don't know why. Maybe because main purpose of HTTP and FTP is sending data, not receiving.

That's why HTTP/FTP servers could break upload session more frequently rather then downloading session.

View more solutions

Comments

[Dejan]

We found this out in the 90's when downloading a file took days ;) +1

[Pyro]

Large or unlimited upload ability could lead to Denial of Service attacks as the attacker fills up your upload file system.

[Thiago Chaves]

Do both of them have built-in support for resuming downloads?

[Thiago Chaves]

Uploads will be controlled in my application. My interest is downloads for now. It is a very valid security concern to limit uploads, if, of course, that is defined on the server. Limiting the client is ridiculous, IMHO.

[Michael Haren]

Yes--it's all browser/server specific. Yes: IE has a 4GB limit

[Piskvor left the building]

Upload is limited on most servers; however, I have yet to see a download size limit.