What is URL encoding (percent-encoding)?

URL encoding, or percent-encoding, replaces characters that aren't safe in a URL — spaces, ampersands, question marks, non-ASCII letters — with a percent sign followed by two hex digits (a space becomes %20). It lets you carry arbitrary text inside a URL without breaking how the URL is parsed.

What's the difference between component and full-URI encoding?

Component encoding (encodeURIComponent) escapes everything that has meaning in a URL — including & ? = # and / — so it's right for a single value such as one query-parameter. Full-URI encoding (encodeURI) leaves those structural characters alone so a whole URL stays usable; it only escapes characters that are never legal in a URL, like spaces. Encode a value with component, an entire link with full URI.

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URL encoder / decoder · free, no signup

Make any string URL-safe.

Percent-encode or decode text in one paste — switch between escaping a single component (encodeURIComponent) and a full URI (encodeURI), then copy the result. Runs entirely in your browser; nothing is uploaded.

URL encoder / decoder

Direction

Encode Decode

Scope

Component Full URI

Input

Output

That isn’t valid percent-encoded text — check for a stray % or an incomplete %XX sequence.

Component escapes & ? = # / too — use it for one value. Full URI leaves a URL’s structure intact. Everything stays on this page; nothing is sent to a server.

Two scopes

Encode a value, or a whole link.

The right choice depends on whether you’re escaping one piece of a URL or the entire thing. Pick the wrong one and you either break the URL or leave it unsafe.

encodeURIComponent

Escapes everything with URL meaning — &, ?, =, #, /, : — so a value can’t break out of its slot. Use it for a single query-parameter value, a slug, or anything you’re dropping into a URL.

encodeURI

Leaves the structural characters that make a URL work untouched and only escapes what’s never legal, like a space. Use it when you have a whole URL and just want to make it safe to paste without scrambling its parts.

Why it matters

A space in a URL is a bug waiting to happen.

URLs only allow a limited set of characters. The moment a value carries a space, an ampersand, an emoji, or a non-Latin letter, the URL has to percent-encode it — otherwise the link truncates, a query parameter swallows the next one, or the whole thing 404s. Encoding by hand is error-prone; one missed % and decoding throws.

Paste your value here to encode it cleanly, or paste an encoded string to read what it actually says. Building campaign links instead? The UTM builder encodes your parameters for you, and the UTM parser decodes a tagged link back into a readable table. Got a short link and want to see where it lands? Run it through the link expander.

Questions

The honest answers.

What is URL encoding?

URL encoding (percent-encoding) replaces characters that aren’t safe in a URL — spaces, &, ?, non-ASCII letters — with a % followed by two hex digits (a space becomes %20). It lets you carry arbitrary text inside a URL without breaking how the URL is parsed.

Component or full URI — which should I use?

Component (encodeURIComponent) escapes everything with URL meaning, including & ? = # / — right for a single value like one query parameter. Full URI (encodeURI) leaves those structural characters alone so a whole URL stays usable. Encode a value with component, an entire link with full URI.

Is it free, and is my text sent anywhere?

Yes — free, no signup, and it runs entirely in your browser, so the text you paste is never sent to slsh.me’s servers. When you’re ready to share a link, every slsh.me short link is free too, with branded slugs and real-time analytics.

Why do I get an error when decoding?

Decoding fails when the input isn’t valid percent-encoded text — a lone % or an incomplete escape like %2 instead of %20. Fix the stray sequence, or switch to Encode if you meant to encode the text rather than decode it.

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Encoded the value? Now shorten the link.

Free forever. No card. Turn that long, encoded URL into a branded slsh.me short link with real-time analytics — the features other shorteners gate behind a paid plan.

Shorten with slsh.me

Tagging a campaign? Use the UTM builder · See pricing