You do not.
We know there are people out there who just want a speedy and free way to touch up photos or make banners or whatever. We respect that wish and do not require an account to use Pixlr Editor on the web. Just jump in and start creating. That said, if you prefer to save what you’re working on and come back to it later, we strongly recommend creating an account. Doing so creates your very own Pixlr Library where you can save all of your images privately.