Base64 Converter
Encode or decode plain text as Base64 instantly in your browser.
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Quick Tip
Choose encode or decode.
About This Tool
Why use Base64 Converter?
Base64 rewrites arbitrary data using 64 safe characters (A–Z, a–z, 0–9, + and /) so it can travel through systems that expect text: JSON fields, data URLs, email attachments and HTTP headers. This converter goes both ways, encoding text to Base64 and decoding it back.
Text is converted through UTF-8 first, so emoji, accented characters and non-Latin scripts encode correctly. Decoding accepts URL-safe Base64 (with - and _ in place of + and /), missing padding and data URL prefixes, which covers most of what you find in tokens and logs. Encoding adds about 33% to the size, since every three bytes become four characters.
Key Benefits
Full Unicode support
Text is encoded through UTF-8, so Hindi, Arabic, Chinese and emoji all survive the round trip.
Forgiving decoder
URL-safe characters, missing padding and data: prefixes are handled without manual cleanup.
Local only
Tokens and credentials pasted here stay in the browser; nothing is transmitted.
How to use Base64 Converter
- 1
Choose encode or decode.
- 2
Paste your text or your Base64 string.
- 3
Read the result and copy it.
- 4
If decoding fails, check that the string is really Base64 and not already plain text.
Best use cases
Read the payload of a JWT while debugging authentication.
Encode a small image or file into a data URL.
Decode a Base64 field from a log or an API response.
Prepare credentials for an HTTP Basic Authorization header.
Base64 Converter FAQs
Is Base64 encryption?
No. It is an encoding, not a cipher — anyone can decode it. Never use it to protect secrets; it only makes binary data safe to transport as text.
Why did my decode fail?
Either the string is not valid Base64, or it decodes to binary data such as an image rather than readable text. Characters outside the Base64 alphabet, or a length that is not a multiple of four after padding, will also fail.
What is URL-safe Base64?
A variant that uses - and _ instead of + and / so the value can sit in a URL without escaping. JWTs use it, and this decoder accepts it.
Why is Base64 bigger than the original?
Every three bytes become four characters, so the output is about 33% larger. That is the cost of representing binary data as text.
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