Base64 Encoder / Decoder

Encode text to Base64 or decode Base64 back to text, with full UTF-8 support. Runs locally — safe for sensitive strings.

● Runs locallyNothing uploadedFree foreverNo sign-up needed

About this tool

Convert plain text to Base64 and back, with correct handling of UTF-8 characters like emoji, Arabic and accented letters that break naive btoa-based tools. Decoding tolerates both standard and URL-safe Base64 variants.

Base64 (RFC 4648) represents binary data using 64 printable characters so it survives systems designed for text — email attachments, data URIs, HTTP basic auth headers, JWT segments. It is an encoding, not encryption: anyone can decode it, so it provides exactly zero secrecy.

How to use it

  1. Type or paste your text (or a Base64 string).
  2. Click Encode or Decode.
  3. Copy the output.

Frequently asked questions

Is Base64 secure?

No. It is a reversible encoding, not encryption. Never treat Base64 as a way to hide secrets — use real encryption for that.

Why is Base64 output longer than the input?

Every 3 bytes become 4 characters, so encoded data is about 33% larger, plus up to two = padding characters.

What is URL-safe Base64?

A variant replacing + with - and / with _ so the string can live in URLs and filenames. JWTs use it. This decoder accepts both.