Base64 String Encoder and Decoder Online

Base64 turns arbitrary bytes into a 64-character ASCII alphabet so text, tokens, and small binary blobs survive transports that only accept plain text — HTTP headers, JSON payloads, URLs, and email. It is an encoding, not encryption: anyone can decode it, so never treat a Base64 string as a secret. Reach for this tool when you need to read what a Base64 value actually contains, or wrap a short string so it travels safely through a text-only channel.

How to use it

  1. Paste or type your text into the input box.
  2. Choose the direction: encode plain text to Base64, or decode a Base64 string back to text.
  3. Read the converted result, and copy it with the copy button.
  4. For decoding, make sure the input is valid Base64 (its length is a multiple of 4, padded with '=' if needed).

Common use cases

Examples

Encode text to Base64

Input Hello, world!

Output SGVsbG8sIHdvcmxkIQ==

Each 3 bytes of input become 4 Base64 characters; '=' pads the final group.

Decode Base64 back to text

Input aXR1dGlsYm94

Output itutilbox

Decoding is the exact inverse — no information is lost.

Frequently asked questions

Is Base64 a form of encryption?
No. Base64 is a reversible encoding with a public algorithm. It hides nothing; use real encryption for secrets.
Why does the output end with one or two '=' characters?
'=' is padding that makes the output length a multiple of 4 when the input byte count is not divisible by 3.
Does this tool send my text to a server?
No. Encoding and decoding run entirely in your browser, so your input never leaves your device.
What is URL-safe Base64?
A variant that replaces '+' and '/' with '-' and '_' so the value can sit in a URL without further escaping.

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