Free Base64 Encoder and Decoder Online

Convert text to and from Base64 with correct UTF-8 handling, so Korean, accents, and emoji round-trip exactly. Decode data URIs and tokens — nothing is uploaded.

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Examples

Encode text to Base64

Input

Hello, 325!

Output

SGVsbG8sIDMyNSE=

Decoding SGVsbG8sIDMyNSE= returns the original Hello, 325! unchanged.

Round-trip a multi-byte string

Input

안녕 👋

Output

7JWI64WVIPCfkYs=

UTF-8 encodes each character to bytes first, so Korean and emoji decode back intact.

How to use this tool

Choose Encode or Decode.
Paste or type your text.
View the converted result instantly.
Copy the output.

What is Base64 Encoder/Decoder?

Base64 Encoder/Decoder converts text to standard Base64 (RFC 4648) and back, handling UTF-8 bytes correctly so multi-byte characters like Korean and emoji survive the round trip instead of turning into mojibake. It is the quick way to read a Base64 chunk from a data URI, a JWT segment, an email header, or a config value, and to produce a Base64 string you can drop straight into one.

Specifications

Standard	Base64 per RFC 4648
Text encoding	UTF-8 (multi-byte safe)
Alphabet	A–Z, a–z, 0–9, + and /, padded with =
Direction	Encode and decode

Tips & gotchas

Base64 is encoding, not encryption — anyone can decode it, so never use it to hide secrets.
Text is treated as UTF-8 before encoding; that is why a 2-character emoji can become several Base64 chars.
Standard Base64 uses + and /. For values placed in URLs you usually need the URL-safe variant that swaps them for - and _.
The trailing = signs are padding to a multiple of 4 characters — they are part of valid output, not an error.

Features

Encode text to Base64
Decode Base64 back to text
Full UTF-8 support (no broken characters)
Clear error messages for invalid input
Copy the result with one click

When to use it

Reading the payload of a JWT or a base64-encoded config value without writing code.
Decoding the text part of a data: URI to see what is actually embedded.
Encoding a small string to paste into a JSON or YAML field that expects Base64.
Inspecting a Base64 chunk from an email header or an API response.

This tool runs in your browser. Your files and text are not uploaded to our servers, and we do not store your input.

Frequently asked questions

Why is the encoded string longer than my text?+

Base64 represents every 3 bytes as 4 characters, so output is about 33% larger than the input. That overhead is the cost of making binary data safe to put in text.

Does it handle Korean, accents, and emoji?+

Yes. Text is encoded as UTF-8 bytes first, so multi-byte characters decode back exactly as typed instead of becoming broken symbols.

Can I use this for URL-safe Base64?+

This tool produces standard Base64 with + and / characters. If a URL or filename needs the URL-safe variant, replace + with - and / with _ after encoding.

Is Base64 a way to encrypt or secure data?+

No. Base64 is reversible encoding with no key, so it offers zero security. Use it for transport and formatting, never to protect sensitive values.