Base64 / URL
Base64 and URL encoding
Base64 represents bytes as printable text; it is encoding, not encryption. URL-component encoding escapes characters that have special meaning inside a URL. Both operations run locally in your browser.
Formula and method
Base64 maps each 24-bit block of input into four 6-bit characters, adding padding when required.
Worked example
The UTF-8 text “hello” encodes as aGVsbG8= in Base64.
How to interpret the result
Base64 converts bytes into a text-safe alphabet; URL encoding escapes characters that have structural meaning in a URL component. They solve different problems and their outputs are not interchangeable. The tool converts plain text to UTF-8 bytes before Base64 encoding so non-ASCII text can round-trip correctly.
Important limitations
- Base64 increases size by roughly one third.
- Do not treat encoded text as secret or protected.
Common questions
Why does Base64 sometimes end with equals signs?
The equals characters pad the final group when the byte length is not divisible by three. Some URL-safe variants omit padding, but a strict decoder may expect it.
Does Base64 protect private data?
No. Anyone can decode it without a key. Use authenticated encryption or a secure transport protocol when confidentiality or tamper resistance is required.
Related tools
Method and examples reviewed September 8, 2026.