URL Encoder/Decoder

Worked example

Example 1: hello world → hello%20world. Example 2: name=R&D → name%3DR%26D so the ampersand does not split query parameters.

When to use this

• Building query strings with special characters.
• Decoding a messy analytics landing URL.
• Preparing values for APIs that expect percent-encoding.
• Round-tripping Unicode in path segments.
• Teaching percent-encoding vs form + encoding.

Common examples

• Space in query value → %20.
• Encode email for mailto query safely.
• Decode %2F vs literal slash in path segments.
• Round-trip Unicode café → %C3%A9 and back.
• Do not encode https:// host—only encode components.

Common mistakes

• Encoding an entire URL including the scheme.
• Double-encoding already escaped values.
• Assuming + always means space in every context.
• Leaving secrets in shareable encoded URLs.
• Encoding slashes that should remain path separators.

How it works

Encodes or decodes URL components with encodeURIComponent / decodeURIComponent semantics—safe for query values, not for encoding an entire URL including ://.

Limitations

Results are based on the inputs you provide and may not cover every edge case. This tool is for general use and is not professional advice.

Privacy and file handling

Your data stays on your device and is not uploaded.

Formula or method

Uses standard percent-encoding for reserved characters. Spaces become %20 (not +); + in decode is treated as a plus character unless you convert form-encoding separately.