if you are looking for a website which gives real time btc transaction fee then you can try this :
https://txfee.org/#A quick check with BTC transaction fee, the site gives the overkilling fee. They suggest 124 sat/vbyte for fastest transaction (next one block ?) but if you check it with another site (that I use and believe it is very accurate), the fee would be 100 sat/vbyte.
https://jochen-hoenicke.de/queue/#1,8hCheck it at the third chart, and hover the computer mouse at the end of the chart to check latest update for size of mempool in different fee rates.
The withdrawalfees.com website is really handy. It shows the minimum, optimum and median withdrawal fees for top cryptocurrencies which is very useful when we are sending cryptocurrencies from one exchange/wallet to another. I have bookmarked this site to quickly get to know the optimum withdrawal fees for any cryptocurrency. I wish there would have been an API for the same so that we could code a program which would send us the optimum withdrawal fee and the coin for which the optimum fees is lowest than the others.
I made this topic for people who need such many details or just one of them, but I would not go to be paranoid about fees like that. It is a waste of time to check many coins only to find out the one that gives you lowest withdrawal or transaction fees.
When you are familiar with crypto, you will have some friendly coins in your list for withdrawal or transactions. Each time you do it, it is a quick check with a few coins only. Four to five coins are enough to change around at different periods.
If I move my big funds (in my capital), I will choose bitcoin. It is the safest chain to move big funds with super high hashrates and cost of attacks are expensive.