JSFiddle - React, Tailwind, and code Playground

JavaScript

var arr = [
    ["pet", "dog", "london", "class"],
    ["pet", "cat", "newyork", "weight"],
    ["tech", "phone", "spain", "hello2"],
    ["tech", "phone", "spain", "hello"],
    ["tech", "phone", "spain", "hello"],
    ["pet", "cat", "newyork", "weight"],
    ["pet", "dog", "london", "class"]
];


var newArr = [];

for (var i = 0; i < arr.length; i++) {
    if (!isArraySame(newArr, arr[i])) {
        newArr.push(arr[i]);
    }
}

console.log(newArr)

function isArraySame(ar, check) {
    var strArr = check.join();
    var isIn = false;
    for (var j = 0; j < ar.length; j++) {
        if (ar[j].join() == strArr){
            isIn = true;
            break;
        }
    }
    return isIn;
}