CODEWITHSUNDEEP
phpinternet-explorerhttppost
invertedSpear
invertedSpear

Reputation: 11054

What is the size limit of an HTTP POST request?

Sorry if this is duplicate,I would think it would be but couldn't find anything.

I have a flex application that I am posting data back to a PHP/MySQL server via Internet Explorer. I haven't run into any problems yet, but knowing this ahead of time might save me a bunch of frustration and work. Is there a size limit to posting data via HTTP?

And it all goes back and forth what I'm able to find online. So please limit answers to personally tested/verified numbers.

I am wanting to post back an XML string that can be quite large (say up to 5mb).

If it makes any difference: browser will always be Internet Explorer (our product requires it), POST is coming from an HTTPService in Flex, web server is PHP, database is MySQL.

Upvotes: 301

Views: 480034

Answers (9)

David
David

Reputation: 25450

The URL portion of a request (GET and POST) can be limited by both the browser and the server - generally the safe size is 2KB as there are almost no browsers or servers that use a smaller limit.

The body of a request (POST) is normally1 limited by the server on a byte size basis in order to prevent a type of DoS attack (note that this means character escaping can increase the byte size of the body). The most common server setting is 10MB, though all popular servers allow this to be increased or decreased via a setting file or panel.

1 Some exceptions exist with older cell phone or other small device browsers - in those cases it is more a function of heap space reserved for this purpose on the device then anything else.

Upvotes: 80

Chris-MindflowAU
Chris-MindflowAU

Reputation: 402

As David pointed out, I would go with KB in most cases.

php_value post_max_size 2K

Note: my form is simple, just a few text boxes, not long text.

(PHP shorthand for KB is K, as outlined here.)

Upvotes: 5

Mira Nedved
Mira Nedved

Reputation: 83

For developers who cannot change php configuration because of the webhosting. (My settings 256MB max size, 1000 max variables)

I got the same issue that just 2 out of 5 big data objects (associative arrays) with substructures were received on the server side.

I find out that the whole substructure is being "flattened" in the post request. So, one object becomes a hundreds of literal variables. At the end, instead of 5 Object variables it is in reality sending dozens of hundreds elementar variables.

Solution in this case is to serialize each of the substructures into String. Then it is received on the server as 5 String variables. Example: {variable1:JSON.stringify(myDataObject1),variable2:JSON.stringify(myDataObject2)...}

Upvotes: 0

brettkelly
brettkelly

Reputation: 28205

It depends on a server configuration. If you're working with PHP under Linux or similar, you can control it using .htaccess configuration file, like so:

#set max post size
php_value post_max_size 20M

And, yes, I can personally attest to the fact that this works :)

If you're using IIS, I don't have any idea how you'd set this particular value.

Upvotes: 223

foobar
foobar

Reputation: 619

By default, the post request has maximum size of 8mb. But you can modify it according to your requirements. The modification can be done by opening php.ini file (php configuration setting).

Find

post_max_size=8M  //for me, that was on line:771

replace 8 according to your requirements.

Upvotes: 3

harpej
harpej

Reputation: 101

One of the best solutions for this, you do not use multiple or more than 1,000 input fields. You can concatenate multiple inputs with any special character, for ex. @.

See this:

<input type='text' name='hs1' id='hs1'>
<input type='text' name='hs2' id='hs2'>
<input type='text' name='hs3' id='hs3'>
<input type='text' name='hs4' id='hs4'>
<input type='text' name='hs5' id='hs5'>

<input type='hidden' name='hd' id='hd'>

Using any script (JavaScript or JScript),

document.getElementById("hd").value = document.getElementById("hs1").value+"@"+document.getElementById("hs2").value+"@"+document.getElementById("hs3").value+"@"+document.getElementById("hs4").value+"@"+document.getElementById("hs5").value

With this, you will bypass the max_input_vars issue. If you increase max_input_vars in the php.ini file, that is harmful to the server because it uses more server cache memory, and this can sometimes crash the server.

Upvotes: 2

Nilesh Chourasia
Nilesh Chourasia

Reputation: 408

You can post large amount of data by setting php.ini variable: max_input_vars Default size of this variable is 1000 but if you want to sent large amount of data you have to increase the size accordingly. If you can't set the size from ini_set you have to do it through htaccess or by doing changes into php.ini file directly.

max_input_vars  2500
memory_limit    256M

Upvotes: 19

Nikolay Ivanov
Nikolay Ivanov

Reputation: 5279

Also, in PHP.INI file there is a setting:

max_input_vars

which in my version of PHP: 5.4.16 defaults to 1000.

From the manual: "How many input variables may be accepted (limit is applied to $_GET, $_POST and $_COOKIE superglobal separately)"

Ref.: http://www.php.net/manual/en/info.configuration.php#ini.max-input-vars

Upvotes: 66

ChrisH
ChrisH

Reputation: 4826

It is up to the http server to decide if there is a limit. The product I work on allows the admin to configure the limit.

Upvotes: 1

Related Questions