How do you unbiasedly evaluate your idea, decide if it's worth it and move on if it's not?

TheMusician has identified some great ways to do some online research. My perspective is that, if possible, qualitative interviews with prospective users is the number one goal for idea validating. You only need between 6-12 (30-45 mins each) to get some great information.

This book is great on idea validation - https://rosenfeldmedia.com/books/lean-user-research/

Gives you plenty of tips on how to conduct an interview too (I do it through Zoom so that I can record it and not have to worry about taking notes).

The key is not asking leading questions to hear the answers that you want to hear. Presumably you have a target user in mind, and a problem that you think they want to solve (with your product). By interviewing target users, you'll get:

• clarity on whether the problem you've identified is a genuine problem for them
• whether it's a big enough problem that they'd pay money to solve
• the language they use to describe the problem (which you can use in your marketing and copywriting)
• maybe a bigger problem that they are really keen to solve, which you could pivot to.

This adds work upfront, but in my experience it's one of the best investments any start-up or indie hacker. It'll save time in the long run, save you going down a rabbit hole and making a product that there isn't a great deal of demand for, and help you create a product that there is a genuine need for. It's so much easier to market a product to a user group that solves a problem they want a solution for, rather than convince them they have a problem (and then convince them they need your solution). It also gives you the raw material to write great copy simply using the quotes and language that they gave you.

The thing I learned is, that validating your product only works with direct interaction with users. There are ways to sort of semi-automate these things, however talking and interacting with users is the main driver for product validation.
The things which are most important are:

• First, conduct research. Are there competitors? If not, it's difficult for an indie hacker, as the market is not established. Is your idea really that unique, that nobody else thought of it?
• Second, again research: About your potential customer market. Engage in communities, learn how they talk, learn about the specifics of their problems. (This by the way was always the thing which I dreaded. Because this sounds like so much work. But surprisingly it isn't. Simply sign up for 3 communities and reserve 2-3h per day for one week - you will get so much knowledge!
• Use google keyword planner or SEMRush to research what SPECIFIC search terms are used to find products like yours
• Then, start sharing your idea, best with not too close friends in your potential customer segment. But also use your social media following. Reach out to whoever might be in proximity of your customer segment - and ask them about their problems. (Do not ask them about your product, and do not try to "sell" your product). Read "The mom test" for a short, funny intro on how to ask questions.
• And than the most important technique for validation: Based on your research and keywords you found, create a landing page. Invite users to either partake in a Waitlist or even better create a "crowdfunding light" program - where you ask your visitors to support you with some € and in exchange they will get lifetime access to your product. You need at least some people willing to at least sign up for the Waitlist to know your product to be validated.
  If nobody signs up, this still does not mean, that your product idea is bad. Change wording, research keywords, ask in your communities about why nobody is interested. And last but not least: Use indiehackers for getting feedback.

Finally, here are some links from IH around this topic:
https://www.indiehackers.com/post/validate-your-product-19-market-testing-and-market-validation-tactics-plus-7-tools-for-validating-df82ddf259
https://www.indiehackers.com/post/my-method-to-validate-your-b2b-idea-582180c961

I don't do anything "unbiasedly" I'm totally biased. I bring all my knowledge, all my experience and every bad bone I got in me when evaluation my idea. and then I just do it.

Personal validation is IF I can't NOT make it. I just keep working on it and working on it and then get external validation in some way.