Depends what you want to do what will be best, but the free version of SurveyMonkey can do some basic things, if your university has Qualtrics it does more, and if you like coding JavaScript is freely available (and there are libraries like jsPsych, that are set up for lots of psychology studies) and is more flexible. Are you planning on using something like MTurk?
Daniel Wright I was thinking about Qualtrics (no, the University has no account, but I think I might get a private subscription for myself...). MTurk - I've never heard of, I'll have a look, thanks for this suggestion.
Pedro Bem-haja Thanks, I'll give it a shot.
Marin Dujmović unfortunatelly I'm not good on coding :( - I know, I have to lose a lot because of that... Thnak you for your answer!
For another payed option take a look at Gorilla (https://gorilla.sc) I've used it recently and it's quite easy to get into and would recommend it for online experiments.
Hi Gabriela Marcu MTurk is Amazon Mechanical Turk. It is a crowd-sourcing system. You can put a study on the web (e.g., on a Qualitrics server), put a notice on MTurk to respondents (add some money to your account) and it points respondents to your survey and sorts out payment. It is used more in the US than elsewhere. It depends what type of sample you are looking for. I actually just posted a study on RG that does this (Deleted research itemThe research item mentioned here has been deleted