Base64 and URL encoding are common in web development, but they solve different problems. Xian's Tools provides:
Both support Chinese and other UTF-8 text, process input locally in your browser, and let you copy the result.
Base64 encoding
What it does
Common uses
- HTTP Basic authentication:
`Authorization: Basic base64(username:password)`. - Representing binary data in JSON or XML.
- Encoding email attachments.
- Inspecting JWT headers and payloads, which use the related Base64URL variant. Standard Base64 and Base64URL use different characters and padding conventions; this tool is a text Base64 utility, not a dedicated JWT parser.
How to use the tool
Open Base64 Encoder and Decoder, enter text, and click Encode or Decode. Text is handled as UTF-8, so non-ASCII input can be decoded correctly in other systems using the same encoding.
Base64 does not protect secrets
Anyone can reverse Base64 encoding. It is not encryption and does not protect passwords or sensitive information. For reversible encryption testing, see AES Encryption and Decryption.
URL encoding
Encoding rules
The tool follows JavaScript's encodeURIComponent. Letters, digits, and - _ . ! ~ * ' ( ) remain unchanged; other characters are encoded. This is useful for individual query parameter values.
Encoding a whole URL also encodes separators such as ://, /, and ?, so the result cannot simply be visited as the original URL. Encode the value instead, for example:
https://example.com/search?q=hello%20worldA % that is not followed by two hexadecimal digits, as in 100%.
- An incomplete UTF-8 sequence, such as
%E4%B8. - Partially encoded or damaged input that leaves invalid escapes.
Double encoding can also produce an unexpected result: one decoding pass may return another encoded string. Check what the receiving system expects before decoding again.
Base64 and URL encoding compared
- Purpose: Base64 represents bytes as text; URL encoding escapes text for use in a URL component.
- Output characters: Base64 uses its fixed alphabet; URL encoding keeps permitted characters and escapes other bytes as
%XX. - Length: Base64 expands bytes by roughly one-third; URL encoding expansion depends on the input and can be much larger for non-ASCII text.
- Encryption: neither provides encryption.
When placing a standard Base64 result in a query parameter, URL-encode the value so characters such as +, /, and = are preserved correctly.
