How to use the Base64 Encoder and Decoder
Paste your text, choose encode or decode, and copy the result. Text is turned into UTF-8 bytes before encoding, so accents and emoji survive the round trip.
How Base64 works
Base64 takes your data three bytes at a time, splits those 24 bits into four groups of 6 bits, and writes each group as one of 64 safe characters: A to Z, a to z, 0 to 9, + and /. The word Man becomes TWFu. Because three bytes turn into four characters, encoded data is about a third larger than the original.
Where you see it
Base64 carries binary data through places that only accept text: email attachments, data URLs for small images in CSS, JSON payloads, and the middle part of a JWT. It is not encryption. Anyone can decode it in a second, so never use it to hide passwords or keys.
How to Base64 decode a string
Paste the Base64 string, choose Decode Base64 and the original text appears. Decoding works in reverse of encoding: each group of four characters becomes three bytes, and those bytes are read as UTF-8 text. If you see an error, the string may be cut short, contain spaces or line breaks from an email, or hold binary data such as an image rather than text.
Base64 and ASCII text
Base64 was designed to encode binary data as plain ASCII characters, because older systems such as email could only carry 7-bit ASCII text safely. Every Base64 string uses just 64 letters, digits and symbols, plus = for padding. Some variants swap + and / for - and _ so the result is safe in URLs and file names.
The formula
Every 3 bytes of input become 4 Base64 characters; = is added as padding at the end when needed.
Examples
- Encode "InovoTools"
SW5vdm9Ub29scw==
- Decode "SGVsbG8gd29ybGQ="
Hello world
Limitations and assumptions
Base64 is encoding, not encryption; do not use it to protect secrets.
Frequently asked questions
Is Base64 encryption?
No. It is an encoding anyone can reverse, so never use it to protect secrets.
Why does Base64 make data larger?
It represents 3 bytes as 4 characters, about 33% larger.
What does the = at the end mean?
Padding to make the length a multiple of 4.
Is my text uploaded?
No. Conversion runs in your browser.