Why did my parameter break when it contained an ampersand?

Because an unencoded & starts a new parameter. Values placed inside a query string must be component-encoded so & becomes %26.

What is the difference between %20 and + for a space?

Both appear. %20 is correct percent-encoding anywhere in a URL; + means a space only inside a query string, under the older form-encoding rules.

Why do non-English characters turn into several % pairs?

They are encoded as UTF-8 first, and a character outside ASCII takes more than one byte — each byte becomes its own percent escape.

URL Encode / Decode

Space as +

Component encodes &, =, /, ? and # — use it for individual query values, not whole URLs.

Type in either pane — conversion runs live in both directions.

Decoded0 chars

Encoded0 chars

URL Inspector

Full URL

Paste a URL to break it into parts and edit its query parameters — or try the Sample.

About URL Encode / Decode

Percent-encode and decode URLs, and break any URL into its parts with a readable query-string table.

What it does

Encode or decode percent-escapes, and paste a whole URL to see it split into scheme, host, port, path, query and fragment — with query parameters listed as a table rather than an unreadable ampersand-separated string. Repeated parameters are shown as repeats rather than silently collapsed.

Component or whole URL

There are two different encoding jobs and mixing them up is the usual bug. Encoding a whole URL must leave the structural characters — : / ? # & = — intact. Encoding a single value that goes inside a query parameter must escape those same characters, or a value containing & will be read as the start of a new parameter. The tool exposes both so you can pick deliberately.

Common questions

Why did my parameter break when it contained an ampersand?: Because an unencoded & starts a new parameter. Values placed inside a query string must be component-encoded so & becomes %26.
What is the difference between %20 and + for a space?: Both appear. %20 is correct percent-encoding anywhere in a URL; + means a space only inside a query string, under the older form-encoding rules.
Why do non-English characters turn into several % pairs?: They are encoded as UTF-8 first, and a character outside ASCII takes more than one byte — each byte becomes its own percent escape.

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