Stocks and Shares ISA - cheapest platform?

[TeaAndHobnob]

I have an S&S ISA with interactive investor with about 4k in it. It started as a bit of fun a few years ago where I just put in £50/month that I wouldn't really notice invested in a few funds.

But now I'm thinking the fees are quite high - 9.99 a month. So that's quite a lot of money really considering there's not much in the pot.

How would I work out if another platform is worth moving to? I know there no exit fees now so that's fine. But I find the fees for various platforms quite confusing. What I want is a tool where I input my current setup and it tells me which is the best value - is there such a thing? If there isn't, how would I go about working out out myself?

There’s a calculator here: www.boringmoney.co.uk/calculator/. It’s says Vanguard would be £6 a year and AJBell £11.50. Both of those are often recommended on these boards.

I use Vanguard but id also check out trading212 ISA option, depends how much money you have to spare :)