How do I use the base64 encoder and decoder?
- Paste your text or Base64 string.
- Choose Encode or Decode.
- Turn on URL-safe if the result goes in a URL or JWT.
- Copy the result.
Base64 encoder and decoder: frequently asked questions
Is Base64 encryption?
No. Base64 is an encoding anyone can reverse. Never use it to hide passwords or secrets.
What is URL-safe Base64?
It swaps + and / for - and _ and drops the = padding, so the string is safe in URLs and JWTs.
What is Base64 used for?
Encoding binary data as plain text so it can travel through systems that only handle text, such as email attachments, data URLs and JSON payloads.
Why is Base64 output larger than the input?
Every 3 bytes become 4 characters, so encoded data is about 33% larger.
Why does decoding give strange characters?
The original data was probably binary, such as an image, or used a different text encoding than UTF-8.
What are the = signs at the end?
Padding, added so the output length is a multiple of 4.
Can I encode Arabic text?
Yes. Text is converted to UTF-8 bytes before encoding, so Arabic round-trips correctly.
Where will I see Base64 in web work?
In JWTs, data URLs for small images, HTTP Basic authentication headers and email MIME parts.
Is there an API for this tool?
Selected tools are available through a rate-limited public API. Contact us if you need higher volumes.
Is the base64 encoder and decoder free?
Yes. It is free with no sign-up and no usage limits for normal use.