[chadscira]

Seems like in chrome you can go much higher!

Here is a example of 5M

    data:text/html,<script>window.location='data:text/html,<!--'+new Array(5000001).join('a')+'!--><script>document.documentElement.innerHTML=window.location.protocol+\':\'+String(window.location).length;</'+'script>';</script>

I tried 110Mb and it actually worked as well! I'm not sure about the real limit.

You can store MASSIVE amounts of data in these things. It also seems to eventually break the url display and reverts to about:blank. It still retains protocol integrity though.