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Free Online URL Tools — Encode, Parse, Build, Validate

30 browser-based URL utilities · updated 20 May 2026

30 free URL tools that run entirely in your browser — encode and decode percent-encoded URLs and Base64URL, parse any URL into its anatomy, build URLs and UTM-tagged campaigns from forms, validate and normalize, extract URLs from messy text, generate QR codes and social share links, decode AMP / SafeLinks / Bitly preview wrappers, check IDN homograph phishing, and build OG / Twitter Card meta tags with mock unfurl previews. Nothing is uploaded — every operation runs locally. No sign-in, no ads, batch mode on every tool.

Encoding and decoding URLs

URL encode / decode round-trips strings between human-readable and percent-encoded form — toggle between encodeURI (whole URL, keeps :/?#&= intact) and encodeURIComponent (every reserved char escaped, for parameter values). Base64URL handles RFC 4648 §5 (URL-safe Base64, the kind JWTs use — - instead of +, _ instead of /, no padding). Data URI builder turns images, SVG, and text into inline data: URIs for CSS and HTML embedding. Punycode / IDN converts internationalized domains to xn--… form and flags mixed-script labels. Batch URL encoder processes thousands of URLs at once — paste a list or CSV, get the result back in the same shape.

Parsing and inspecting

URL parser breaks any URL into scheme, user, host, port, path segments, decoded query parameters (as an editable table), and fragment, plus the WHATWG-normalized form. Query-string editor gives you a draggable, dedupe-able table for any ?key=value string. JWT decoder decodes the header and payload of a JWT and tells you whether it's expired (no signature verification — that needs the secret). URL diff shows what's different between two URLs piece by piece — green for same, red for different, yellow for one-sided. URL explainer describes a URL in plain English, recognising common tracking parameters and what each platform uses them for.

Building and generating

URL builder composes URLs via labeled fields with live preview; templates save to LocalStorage. UTM builder handles the full Google Analytics campaign-tag lifecycle with channel presets and a recent-history pane. UTM cleaner strips tracking parameters (UTM, gclid, fbclid, mc_cid, _ga) with a one-click button. Slug generator turns titles into URL-safe slugs with WordPress / Ghost / Hugo / GitHub-anchor presets and Unicode transliteration. QR code from URL outputs SVG and PNG with optional centre logo and error-correction control. mailto / tel / sms builds clickable links for email, phone, SMS, and FaceTime. geo / magnet / crypto URIs generates niche schemes from form fields. Social share links produces share-intent URLs for X, Facebook, LinkedIn, Reddit, WhatsApp, Telegram, Bluesky, and email in one batch. URL → Markdown link converts URLs to Markdown, HTML, BBCode, Slack mrkdwn, or reST.

Validating and checking

URL validator checks one URL or a list against the WHATWG spec — strict or lenient mode, with the exact character position of any error. URL normalizer canonicalises URLs with RFC 3986 §6 plus optional rules — sort params, drop default port, lowercase host, force trailing slash. Redirect URL decoder unwraps Google AMP, Google Search redirects, Facebook l.php, Outlook SafeLinks, YouTube short links, Bitly preview pages, LinkedIn lnkd.in previews, and t.co — all pattern-based, no network call. IDN homograph checker catches phishing domains that mix Cyrillic, Greek, or other lookalike characters with Latin in the same label. Deep-link syntax tester validates iOS Universal Link, Android App Link, and custom-scheme URIs and emits the matching apple-app-site-association / assetlinks.json entries.

Extracting and transforming

Extract URLs from text pulls URLs out of any blob — plain text regex, HTML attributes, Markdown link syntax, or auto. Domain / host extractor converts a URL list into unique hostnames or eTLD+1 using the in-browser Public Suffix List. URL sorter / deduper normalizes, sorts, and deduplicates a list with your choice of rules. Favicon URL builder generates the four standard favicon URL patterns (own /favicon.ico, Google S2, DuckDuckGo, Icon Horse) with side-by-side preview.

Previewing and sharing

OG / Twitter Card meta builder generates Open Graph + Twitter Card + Schema.org <meta> tags from a form, with mock previews of how Slack, Discord, X, LinkedIn, Facebook, iMessage, and Telegram will unfurl your URL. URL fingerprint produces a one-page health card with SHA-256, length, char-class histogram, and suspicious-pattern flags — a starting point, not a verdict.

What every tool has in common

Everything runs in your browser. The URLs you paste, the files you drop, and the data you build — none of it is transmitted to any server. There is no upload step, no fetch against an arbitrary host (CORS would block that for most useful targets anyway), and no account system. Verify it yourself in the browser's Network tab: after the page loads, paste anything you like — the Network tab stays silent. See the privacy policy for the longer version.

Batch mode by default. Every tool that operates on a single URL also accepts a list. Paste one or many; the same encode / normalize / extract / validate logic runs on each row, with progress for large batches. CSV in, CSV out where it matters.

We don't fetch your URLs. CORS prevents the browser from following arbitrary cross-origin redirects, fetching live Open Graph metadata, or screenshotting third-party pages — so we don't pretend to. For each of those we either pattern-match (the redirect decoder unwraps known wrappers without a network call), produce a mock preview (the OG builder), or give you a one-line curl command to run on your terminal (the deep link tester).

Free to use, with no warranty. Read the terms of use before relying on the output for anything load-bearing. Bug reports and feature requests are always welcome — drop me a line.

— S., [email protected]