Base64 Encode & Decode
Encode text to Base64 or decode it back, with URL-safe and MIME options and correct UTF-8.
URL Encode & Decode
Runs on your device Processed locally in your browser. Nothing is uploaded.
Percent-encode or decode URL components, full URLs and form data, with correct UTF-8.
How to use
- Choose Encode or Decode.
- Pick the mode: Component for a single value such as a query parameter or path segment, Full URL to encode a complete address while keeping its structure, or Form for HTML form data.
- Type or paste your text. The result updates as you type.
- Copy the result, or select Swap to move it into the input and reverse the direction.
Method
Component mode percent-encodes every UTF-8 byte except the unreserved characters
A–Z a–z 0–9 - . _ ~ (RFC 3986 §2.3), with uppercase hex digits — ₹ becomes %E2%82%B9.
Full URL mode also keeps the reserved characters : / ? # [ ] @ ! $ & ' ( ) * + , ; = and any
valid %XX escapes already present, so the address keeps its structure. When decoding in this mode,
escapes of reserved characters are kept, so the URL's meaning does not change.
Form mode works like Component mode, except that a space is written as + and + decodes to a
space, as in application/x-www-form-urlencoded (WHATWG URL Standard).
Decoding checks every %XX escape and the UTF-8 it produces; a malformed escape or invalid UTF-8
shows a clear error instead of a partly decoded result.
Browser-based processing. The text is encoded and decoded on your own device, in a background worker, and never sent to a server.
FAQ
When should I encode a component vs a full URL?
Encode a component when you insert one value into a URL — a search term, a file name or a redirect address. Component mode encodes every character except letters, digits and - . _ ~, so characters such as &, = and / can't change the meaning of the URL. Full URL mode keeps reserved characters such as :, /, ?, & and =, and existing %XX escapes, so the address still works; it encodes spaces, non-ASCII characters and other unsafe characters.
Why do spaces become %20 or +?
In a URL, a space is encoded as %20. In HTML form data (application/x-www-form-urlencoded) a space becomes +. Use Form mode for query strings produced by HTML forms, and Component mode everywhere else.
Why does decoding fail?
Decoding fails when a % is not followed by two hexadecimal digits — for example %G1 or a lone % — or when the decoded bytes are not valid UTF-8 text. The error message tells you which problem was found.
References
- RFC 3986 — Uniform Resource Identifier (URI): Generic Syntax (rfc-editor.org)
- WHATWG URL Standard — application/x-www-form-urlencoded (url.spec.whatwg.org)