When searching on pathofexile.com/trade, this addon inserts the tilde(~) before your search query. This enables fuzzy search, so you can be more lenient with your search. Start you search with a space (" ") to not use fuzzy search for this query.

poe2_fuzzy_search.user.js

// ==UserScript==
// @name         PoE2 Fuzzy Search
// @namespace    http://tampermonkey.net/
// @version      1.0
// @description  Prepends ~ to non-space starting queries and removes leading spaces
// @author       Kevin M. (inspired by /u/posturecheck3859738 on /r/pathofexile)
// @match        https://www.pathofexile.com/trade2*
// @icon         https://www.google.com/s2/favicons?domain=pathofexile.com
// @downloadURL  https://gist.github.com/Krytos/2ae5bd9aba4dc98c2dbc98c94f26d4eb/raw/poe2_fuzzy_search.user.js
// @grant        none
// ==/UserScript==


(function() {
    'use strict';
    let isProgrammaticChange = false;

    function handleInputEvent(e) {
        if (isProgrammaticChange) return;

        const input = e.target;
        let val = input.value;

        // Reset session when empty
        if (input.spaceSession && val === '') {
            input.spaceSession = false;
            return;
        }

        // Handle existing space session
        if (input.spaceSession) return;

        // Process new input
        if (val.startsWith(' ')) {
            const trimmed = val.trimStart();

            if (trimmed.length > 0) {
                isProgrammaticChange = true;
                input.spaceSession = true;
                input.value = trimmed;

                // Update React's state
                const nativeInputValueSetter = Object.getOwnPropertyDescriptor(
                    window.HTMLInputElement.prototype, "value"
                ).set;
                nativeInputValueSetter.call(input, trimmed);
                input.dispatchEvent(new Event('input', { bubbles: true }));

                setTimeout(() => isProgrammaticChange = false, 0);
            }
        }
        else if (val.length > 0 && !val.startsWith('~')) { // Modified condition
            isProgrammaticChange = true;
            input.value = '~' + val;

            const nativeInputValueSetter = Object.getOwnPropertyDescriptor(
                window.HTMLInputElement.prototype, "value"
            ).set;
            nativeInputValueSetter.call(input, '~' + val);
            input.dispatchEvent(new Event('input', { bubbles: true }));

            setTimeout(() => isProgrammaticChange = false, 0);
        }
    }

    // Mutation Observer setup
    const observer = new MutationObserver(mutations => {
        const targetInput = document.querySelector(
            'div.multiselect.filter-select-mutate input.multiselect__input'
        );

        if (targetInput && !targetInput._modified) {
            targetInput._modified = true;
            targetInput.spaceSession = false;
            targetInput.addEventListener('input', handleInputEvent);
        }
    });

    observer.observe(document.body, {
        childList: true,
        subtree: true
    });

    // Initial setup
    const existingInput = document.querySelector(
        'div.multiselect.filter-select-mutate input.multiselect__input'
    );
    if (existingInput) {
        existingInput._modified = true;
        existingInput.spaceSession = false;
        existingInput.addEventListener('input', handleInputEvent);
    }
})();