getURL vs. window.location: When to Use Each Method

getURL Explained: How to Retrieve and Manipulate URLs in Your AppURLs (Uniform Resource Locators) are the addresses users and applications use to locate resources on the web. Retrieving and manipulating URLs is a common task in web development—used for routing, analytics, state management, deep linking, and building dynamic links. This article explains how to get, parse, update, and safely handle URLs across environments: browser, server, and mobile/webviews. It includes practical examples, best practices, and security considerations.

Why URL handling matters

URLs carry the user’s intent (query parameters, path, fragments) and can be used to reconstruct app state.
Proper URL manipulation enables shareable links, bookmarking, progressive enhancement, and SEO-friendly routing.
Mishandling URLs can break navigation, degrade UX, or introduce security vulnerabilities such as open redirect and injection attacks.

Retrieving the current URL in the browser

Using window.location

In modern browsers the most direct way to get the page URL is window.location. It exposes several useful properties:

window.location.href — full URL as a string (including protocol, host, path, query, fragment).
window.location.protocol — scheme (e.g., “https:”).
window.location.host — hostname plus port.
window.location.pathname — path component (e.g., “/products/42”).
window.location.search — query string starting with “?” (e.g., “?q=shoes&page=2”).
window.location.hash — fragment identifier starting with “#” (e.g., “#section3”).

Example:

const currentUrl = window.location.href; console.log(currentUrl);

Using the URL interface

The standard URL constructor provides a parsed, mutable representation of a URL:

const url = new URL(window.location.href); console.log(url.protocol, url.hostname, url.pathname, url.search, url.hash);

URL objects allow easy manipulation of query parameters via url.searchParams:

url.searchParams.set('page', '3'); url.searchParams.append('tag', 'sale'); console.log(url.toString());

Parsing arbitrary URL strings

When you receive a URL string (from user input, API, or config), use the URL constructor to parse it:

try {   const parsed = new URL('https://example.com/path?x=1#frag');   // use parsed.hostname, parsed.pathname, parsed.searchParams } catch (err) {   // invalid URL }

For relative URLs within a page, provide a base:

const parsedRelative = new URL('/images/photo.jpg', window.location.origin);

Manipulating URLs without reloading the page

Changing query params and hash with History API

To update the visible URL without a page reload, use history.pushState or history.replaceState together with location.href or the URL object.

history.pushState(stateObj, title, url) — adds a new history entry.
history.replaceState(stateObj, title, url) — replaces current history entry.

Example — updating query string:

const url = new URL(window.location.href); url.searchParams.set('filter', 'popular'); history.replaceState({}, '', url.toString());

Example — adding a fragment:

const url = new URL(window.location.href); url.hash = 'reviews'; history.pushState({}, '', url.toString());

Using libraries and frameworks

Many frameworks abstract URL manipulation:

React Router uses declarative routes and offers useHistory/useNavigate to manage URL state.
Next.js provides router.push and router.replace.
Vue Router exposes router.push/replace and reactive route objects.

Building URLs programmatically

To construct URLs reliably:

Use the URL constructor to avoid manual concatenation mistakes.

Use encodeURIComponent for components you add manually (path segments, query values). Example:


const base = 'https://api.example.com'; const endpoint = '/search'; const q = 'red shoes'; const url = new URL(endpoint, base); url.searchParams.set('q', q); console.log(url.toString()); // https://api.example.com/search?q=red+shoes

For RESTful path parameters, prefer path templating libraries or carefully encode segments:

const userId = 'john/doe'; const url = new URL(`/users/${encodeURIComponent(userId)}`, 'https://example.com');

Server-side URL handling (Node.js)

In Node.js you can use the WHATWG URL API (global URL) or the legacy url module:

// WHATWG URL const { URL } = require('url'); const url = new URL('https://example.com/path?x=1'); console.log(url.pathname, url.searchParams.get('x'));

When handling incoming HTTP requests (e.g., with Express), the request object provides URL parts:

app.get('*', (req, res) => {   console.log(req.originalUrl); // path + query   console.log(req.protocol, req.hostname); });

To build absolute URLs on the server, combine known protocol/host (from headers or configuration) and request path instead of trusting user-supplied Host headers.

Mobile apps and webviews

Native mobile apps should construct URLs using platform utilities or URL libraries to ensure proper encoding, especially when deep-linking.
In webviews, window.location and the URL object behave like in the browser, but interaction with the native layer may use custom schemes (myapp://).

Common patterns and examples

Read a query parameter:

const url = new URL(window.location.href); const page = url.searchParams.get('page') || '1';

Add UTM parameters for marketing:

const url = new URL('https://example.com/promo'); url.searchParams.set('utm_source', 'newsletter'); url.searchParams.set('utm_medium', 'email'); console.log(url.toString());

Toggle a filter state in single-page apps:

function toggleFilter(key, value) { const url = new URL(window.location.href); if (url.searchParams.get(key) === value) { url.searchParams.delete(key); } else { url.searchParams.set(key, value); } history.replaceState({}, '', url.toString()); }

Security considerations

Validate and normalize incoming URLs. Don’t blindly redirect to user-provided URLs (open redirect risk).
Use a whitelist of allowed hosts or validate origins before following or embedding external URLs.
Encode path segments and query values with encodeURIComponent or the URL API.
Strip or validate fragments and credentials embedded in URLs (e.g., user:pass@host).
Be careful with URL-based sensitive state (avoid placing secrets in query strings or fragments).

Performance and SEO tips

Prefer descriptive, stable paths for SEO (example.com/products/blue-widget) rather than long query strings where possible.
Use canonical links () to indicate the preferred URL when multiple URLs map to the same content.
Minimize URL changes that trigger full page reloads on navigation in single-page apps; use history API to keep navigation smooth.

Testing and debugging URLs

Log or display URL components during development.
Use browser devtools to inspect history entries and current location.
For server apps, add unit tests around URL parsing/creation to catch encoding errors.

Summary

Use window.location and the URL API in browsers for reliable parsing and manipulation.
Use history.pushState/replaceState to update the visible URL without reloading.
Prefer the URL constructor over string concatenation to avoid encoding errors.
Validate external URLs and use whitelists to prevent open redirects and injections.

This overview gives you the tools and patterns to reliably work with URLs across client, server, and mobile contexts—making your app more navigable, shareable, and secure.