[gab_]

Yes, of course, but at the moment the site is only there to try out my idea and evaluate its potential.

[farbklang]

That doesn't matter. Impressumspflicht means it's your pflicht to have an Impressum. You can also get an Abmahnung as an individual.

[WhatsName]

That is in principle correct, but since OP is using a throwaway and a know anonymous domain service. As long as he burns bridges after himself (eg. not making it into a adressable business later), there is not individual to deliver a letter to.

Might work for a while, but a dangerous game to play...

[echoangle]

It’s a bit more nuanced, you don’t need a Impressum for purely personal websites without financial background. Evaluating a business idea would probably count as financial motive though, even if it isn’t currently monetized.

[slightwinder]

Impressumspflicht only applies for commercial interests. If you are a company informing or even selling something, if you are an influencer making money of yourself, or even if you just have ads on your Pokemon-fanpage, then it counts as commercial interest.

But I don't see any direct monetary value on this site at the moment. There is not even a reputation-gain, as there is no personal information. So Impressumspflicht would not apply.

[lukan]

Likely nothing will happen, but the way it looks, it is not obvious it is only for testing and you now posted it in the open and there seems a comercial intent. The law is quite clear there last time I checked, it needs an adress. (Even for uncomercial projects it seems advisable).