TL;DR — paste, pick a mode, copy the encoded or decoded result
This free URL encoder/decoder supports URI, URIComponent, Query Value (+), and RFC 3986 modes. Use Batch lines for lists, preserve slashes when needed, normalize percent case, inspect UTF‑8 bytes, and view a quick URL breakdown with query parameters. Everything runs locally in your browser.
URL Encoder & Decoder – Encode & Decode URLs Online (URI, URIComponent, RFC 3986)
Encode or decode URLs online using URI, encodeURIComponent, Query Value (+), or RFC 3986 mode. Includes batch line processing, UTF-8 byte inspector, query parameter table, and one-click copy — all client-side. Choose URI for whole links, URIComponent for individual query values, Query Value (+) for HTML form-style spaces, or RFC 3986 for strict, predictable component encoding. As you type, the opposite pane updates instantly (you can turn auto‑sync off if you prefer manual control).
Beyond the basics, there’s power when you need it: a Batch lines switch to process lists line‑by‑line, a Keep "/" option to preserve slashes in component encodes, and Normalized output that uppercases hex digits in %XXsequences for cleaner diffs and reviews. The Byte / UTF‑8 inspector reveals raw bytes and percent forms—a quick way to verify multibyte characters. If you paste a full link into the Decoded pane, the app shows a URL breakdown (protocol, host, path, query, hash) and a query parameter table so you can see decoded values alongside their encoded forms.
It’s all client‑side for speed and privacy—no uploads, no accounts. One‑click Copy sits on both panes, and handy Swap/Clear buttons streamline repetitive tasks. Whether you’re building query strings, debugging redirects, preparing HTTP links, or cleaning web‑form input, this is the compact utility you’ll keep pinned in your toolbox.
encodeURI vs encodeURIComponent — when to use each
encodeURI is designed for whole URLs. It preserves structural characters like :, /, ?, &, and =, so the URL remains valid after encoding. Use it when you need to make a full link safe for transport without breaking its structure.
encodeURIComponent is for individual query values or path segments. It encodes separators like /, ?, &, and = so they cannot alter the URL structure. Use it when embedding a value inside a query string — for example, a search term, a redirect URL, or any parameter that may contain special characters.
How to use the URL Encoder / Decoder
- Pick a mode: URI for whole URLs; URIComponent for parts; Query Value (+) for form values; RFC 3986 for strict component encoding.
- Paste or type: Use the Decoded pane to encode, or the Encoded pane to decode. With Auto‑sync on, the opposite side updates instantly.
- Adjust options: Turn on Batch lines for lists, enable Keep "/" to preserve slashes, and check the Normalized result for uppercase percent sequences.
- Inspect details (optional): Expand the Byte / UTF‑8 inspector to see raw bytes and percent forms. If a full URL is present, review its breakdown and the query parameter table.
- Copy or swap: Copy with one click, Swap sides to invert direction, or Clear both panes to start fresh.
Key features
- Encode/decode with four modes: URI, URIComponent, Query Value (+), RFC 3986
- Batch lines to process each line separately
- Keep '/' unencoded for readable paths when needed
- Percent normalization (uppercase %XX) for consistent diffs
- UTF‑8 byte inspector with percent‑form preview
- Automatic URL breakdown: protocol, host, port, path, query, hash
- Query parameter table with decoded and encoded views
- Swap & Clear utilities plus one‑click Copy on both panes
- Instant, client‑side operation — private and fast
Tips
- Use URI for entire links; use URIComponent for parts like query values or path segments.
- Choose Query Value (+) when working with HTML form data (spaces as +).
- Turn on Batch lines to convert a list without touching formatting.
- 'Keep /' is useful when encoding path segments but you still want slash separators.
- If decoding fails, look at the error index and the Normalized output to spot stray % or mixed encodings.
- Use the byte inspector to verify UTF‑8 boundaries for non‑ASCII characters.
Frequently asked questions
encodeURI vs encodeURIComponent — which should I pick?
/ ? & =) intact. encodeURIComponent is for individual parts such as a query value or a path segment; it encodes separators so they cannot break the URL structure.When do spaces become + instead of %20?
+. Standard percent‑encoding encodes spaces as %20. Use Query Value (+) mode when you need the form behavior.What does RFC 3986 mode change?
~ unencoded and percent‑encodes characters like ! * ' ( ). Many APIs prefer this predictable output.How does the Normalized output help?
%2f → %2F), which makes diffs consistent and helps spot mixed or duplicated encodings.Can I inspect bytes for non‑ASCII characters?
Is any data uploaded?
How do I decode a URL-encoded string online for free?
hello%20world) into the input box, select Decode, and the readable text appears instantly. No account or software needed.How do I encode special characters in a URL?
&, =, #, and spaces. Use encodeURI only for complete URLs where you need to preserve structural separators.Why does my URL show %3A and %2F instead of : and /?
%3A is the URL-encoded form of : and %2F is /. This happens when encodeURIComponent is applied to a full URL instead of individual query values. Use the URI mode or decode the string to restore the original characters.