Base64 Encoder / Decoder
Encode text to Base64 or decode Base64 back to text, entirely in your browser, with a URL-safe variant for use in URLs and filenames. Base64 represents arbitrary bytes using 64 safe characters (A–Z, a–z, 0–9, + and /), so binary or non-ASCII data can travel through systems built for plain text — email bodies, JSON fields, data: URIs and HTTP headers. Encoding uses UTF-8, so accented letters, emoji and any Unicode round-trip correctly. Because everything runs locally, you can encode secrets or tokens without sending them anywhere. Note that Base64 is an encoding, not encryption: anyone can decode it, so it guards against corruption in transit, not against being read.
How to use
- Choose Encode or Decode.
- Type or paste your text into the input.
- For encoding, optionally enable URL-safe output.
- The result appears instantly below.
- Copy the output with the Copy button.
Frequently asked questions
- Does it support Unicode and emoji?
- Yes. Text is encoded as UTF-8 first, so any character including emoji round-trips correctly.
- What is URL-safe Base64?
- It replaces + and / with - and _ and drops padding, so the result is safe in URLs and filenames.
- Is my text uploaded?
- No. Everything is processed locally in your browser.
- Why does decoding fail?
- The input isn't valid Base64. Check for stray characters or incomplete data.
- Is Base64 a form of encryption?
- No. Base64 is a reversible encoding with no key — anyone can decode it instantly. It exists to carry binary data safely through text-only channels, not to keep data secret. For confidentiality you need actual encryption.
- Why is the encoded output larger than the input?
- Base64 represents every 3 bytes as 4 characters, so the output is about 33% larger than the input. That overhead is the price of using only text-safe characters, and it is expected.
Guides on this topic
- Number Bases and Text Encodings: A Developer's Cheat Sheet A practical primer on binary, octal, decimal and hexadecimal, plus how text becomes bytes through UTF-8, Base64 and URL encoding — with the rules you actually need.
- Hashing vs Encryption vs Encoding: What's the Difference Three terms that are constantly confused — hashing, encryption and encoding — explained clearly, with what each is for, when to use which, and the mistakes to avoid.
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