Bytelify

Base64 Encoder

Encode text to Base64 instantly, live as you type, Unicode-safe.

Runs in your browser, nothing sent
base64-encoder
Both sides are live. Edit either one.Need to decode instead? Base64 Decode Online (Base64 Decoder)

What is Base64 Encoder?

Base64 is a binary-to-text encoding scheme that represents raw bytes using only 64 printable ASCII characters, making binary data safe to embed in places designed for plain text, such as JSON payloads, email attachments (MIME), data URIs in HTML/CSS, and HTTP Basic Authentication headers. Type any text and get its Base64-encoded form instantly, with both directions wired together: edit either the plain text or the Base64 field and the other updates live. The encoder is safe for Unicode text (emoji, accented characters, and more), since it encodes via UTF-8 bytes rather than the older Latin1-only btoa(), which corrupts any character outside that range. Base64 encoding is not encryption. It's a reversible, publicly documented transformation with no secret key, so anyone can decode it back to the original data; don't use it as a substitute for actually securing sensitive information.

How to Use the Base64 Encoder

  1. 1

    Type or Paste Plain Text: Enter any text in the plain-text field, including Unicode characters like emoji and accented letters.

  2. 2

    Read the Base64 Result Instantly: The encoded output appears automatically in the Base64 field as you type.

  3. 3

    Edit Either Field: Both fields are live: editing the Base64 field directly decodes it back into the plain-text field.

  4. 4

    Copy the Result: Use the copy button to copy whichever value you need.

How Base64 Encoding Works

Base64 re-encodes raw bytes using only 64 characters that are safe for text-based formats: A-Z, a-z, 0-9, plus + and / (with = as padding). The input is grouped into chunks of 3 bytes (24 bits) and each chunk is split into four 6-bit pieces. Each 6-bit piece (a value 0-63) maps to one Base64 character, which is why every 3 bytes of input become exactly 4 characters of output. When the input length isn't a clean multiple of 3 bytes, one or two = padding characters are appended so the output length is always a multiple of 4.

Example

Before
Hello, World!
After
SGVsbG8sIFdvcmxkIQ==

Every character round-trips safely, including punctuation, emoji, and accented text — this is the tool's own live output, not a hand-typed sample.

FAQs

Frequently Asked Questions

Common questions about Base64 Encoder.

Yes. It encodes through TextEncoder/UTF-8 first, so accented characters, emoji, and other Unicode text round-trip correctly, unlike the browser's raw btoa().

No practical limit for typical use. Everything happens in memory in your browser.

No. Base64 is encoding, not encryption. It has no secret key, and anyone can decode it back to the original data; it does not protect sensitive information.

Base64 processes input in 3-byte chunks to produce 4-character groups. When the input length isn't a multiple of 3 bytes, one or two = padding characters are appended so the output stays a clean multiple of 4 characters.

Each 3 bytes of input becomes 4 characters of output, so Base64 is roughly 33% larger than the original data. This overhead is the trade-off for making arbitrary binary data safe inside text-only formats.

Common uses include embedding images directly in HTML/CSS as data URIs, encoding email attachments (MIME), encoding credentials in HTTP Basic Authentication headers, and storing binary data inside JSON or XML, none of which can safely carry raw binary bytes.

Yes, Bytelify's Base64 Encoder is free with no account or sign-up required.

No. The encoding runs entirely client-side in your browser, so nothing you type is sent anywhere.