URL Encoder / Decoder

When marketers need to encode text

URLs can only safely carry a limited set of characters. Spaces, ampersands, question marks, plus signs, and non-ASCII characters all have special meanings or aren’t allowed at all, so they have to be converted — percent-encoded — before they go into a link. A space becomes %20, an ampersand becomes %26, and so on.

This comes up constantly in campaign work:

• UTM values with spaces or special characters. utm_campaign=Spring Sale & Launch breaks the query string; the encoded form Spring%20Sale%20%26%20Launch survives.
• Destination URLs inside other URLs. Redirect and click-tracking links carry a target URL as a parameter, and that inner URL must be fully encoded or everything after its first & is lost.
• Pre-filled form and mailto links. Subject lines and body text in mailto: links need encoding to display correctly.
• Debugging links from emails. Paste a mangled link in decode mode to see what it actually says.

Paste your text and the tool shows three outputs at once. Toggle decode mode to reverse the process.

The three output formats

• URL component uses encodeURIComponent, which encodes every reserved character. Use this for individual parameter values — never for a whole URL, since it would also encode the :// and ? that the URL needs.
• Base64 converts text into a compact alphanumeric form. Some ad platforms, data URIs, and APIs expect Base64 payloads. It is an encoding, not encryption — anyone can decode it.
• HTML entities escapes &, <, >, ", and ' so text can be embedded safely in HTML — useful when pasting copy or URLs into raw email templates without breaking the markup.

Frequently asked questions

What’s the difference between encoding a URL and encoding a URL component?

Encoding a full URL (encodeURI) leaves structural characters like :, /, ?, and & intact so the URL still works. Encoding a component (encodeURIComponent) converts those too, which is what you want when a value — including an entire other URL — is being placed inside a query parameter.

Why does my decoded text still contain % signs?

It was probably encoded twice. Links that pass through multiple tools (a shortener, then an email platform) sometimes get encoded at each step, turning %20 into %2520. Run decode again until the text stops changing.

Is Base64 a way to hide or protect data?

No. Base64 is trivially reversible and offers no security at all. Use it only when a system requires that format, never to conceal anything sensitive.

Should I encode my whole UTM link before sharing it?

No — encode only the parameter values, then assemble the link. If you encode an already-assembled link, the ? and & separators get encoded too and analytics tools will see one long meaningless parameter. The UTM builder handles value encoding automatically.