@PixyYeah, I routinely use each of those, though most of WordHippo's are overly vague, often similar, rather than true synonyms, so searching through their listings can be frustrating (I normally scan the first several, as after those, they're rarely useful.
I've always found, that clicking on a normal thesaurus' synonym's, often leads to more accurate synonyms for your original inquiry.
Also, traditional dictionaries and thesauruses often exclude a whole LOT of the informal references, so another handy references is Urban Dictionary. Also, it's always important to differentiate between American, Imperial, Australian and British language variations (if it's necessary) as the meanings can often vary from one English dialect to another.