How to show all rows in the jqGrid?

In the latest version of jqGrid, you can set rowNum to -1 to instruct the grid to always display all rows:

rowNum: -1

See the latest jqGrid documentation here.

Specifically:

Sets how many records we want to view in the grid. This parameter is passed to the url for use by the server routine retrieving the data. Note that if you set this parameter to 10 (i.e. retrieve 10 records) and your server return 15 then only 10 records will be loaded. Set this parameter to -1 (unlimited) to disable this checking.

Update

Unfortunately this behavior was broken in jqGrid 3.6.3. According to this post from Tony:

Yes, this is true. The reason is the new introduced scroll:1. In the future we will correct this behavior.

So the jqGrid developers are aware of this problem and apparently are planning to fix it in a future release. Unfortunately this post was from over a year ago...

At this time, all I can recommend is that you set rowNum to a very large number to simulate the behavior of -1.

You can also try whatispunk's solution below of using rowNum: ''. However, I tried this on a grid containing local data (loadonce: true). When attemping to sort the rows all of the grid's local data would disappear. So this solution does not seem to work for grids with local data, unless this defect has been fixed in a later version of jqGrid (I tested it on jqGrid 3.8.2). If you have feedback, please post a comment below!

According to the jqGrid team this is now fixed:

I have added support to set different display values on pager select box including -1 for all.

I have not had a chance to test to confirm the fix, though. Presumably this change will be in the next release after jqGrid 4.6.0.

jqgrid (3.5 anyway) doesn't seem to have an elegant built in way to do this. The best I have found so far is to add something like the following to your grid options:

rowList:[10,20,30,100000000],
loadComplete: function() {
    $("option[value=100000000]").text('All');
},

Where the 100000000 is some arbitrarily higher number than the maximum # of rows you will ever return, and the option[value=] line is so your user interface looks a little nicer. Jenky, but works for me.