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Base64 Encoder

Encode text to Base64 in your browser — full Unicode support, standard Base64 output.

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Quick Answer

Base64 Encoder turns text into a Base64 string, in your browser. It first encodes your text as UTF-8, so anything — accents, emoji, non-Latin scripts — converts correctly, then represents those bytes in standard Base64 (the A–Z, a–z, 0–9, plus + and / alphabet). Base64 is about 33% larger than the original. Nothing is uploaded, and the result is ready to copy.

What the Base64 Encoder Does

Base64 turns text or bytes into a plain set of ASCII characters that survive systems built only for simple text — embedding a token in a config, putting data in a URL or a data URI, or moving content through a channel that mangles anything unusual.

This encoder is built for text, and it handles Unicode properly: it converts your text to UTF-8 first, so an emoji or a character with an accent encodes without errors — the trap that catches naive Base64 tools.

How It Works

Your text is first turned into UTF-8 bytes, the standard way to represent any character as a sequence of bytes. That step is what lets the encoder accept Unicode rather than only plain ASCII.

Those bytes are then grouped three at a time and mapped to four Base64 characters from the standard alphabet (A–Z, a–z, 0–9, +, /), with = padding at the end. That three-bytes-to-four-characters expansion is why Base64 runs about a third larger than the input.

Data source & conversion logic

  1. Step 1. Type or paste the text to encode — it stays in your browser, never uploaded.
  2. Step 2. The text is converted to UTF-8 bytes (so Unicode and emoji work).
  3. Step 3. Bytes are grouped in threes and mapped to four Base64 characters each.
  4. Step 4. Padding (=) is added so the length is a multiple of four.
  5. Step 5. Copy the standard Base64 output.

Privacy

The text you encode never leaves your browser — there is no upload and no server copy. That keeps tokens, keys, and private strings on your own machine.

Nothing is stored and there is no account. Clear the box or close the tab and the text and its Base64 are gone from memory.

Technical Details

DirectionText → Base64
AlphabetStandard Base64 (A–Z a–z 0–9 + /, = padding)
UnicodeFull — text is UTF-8 encoded first
SizeAbout 33% larger than the input
ScopeText (for files, use Image to Base64)
UploadNever — runs in your browser

Standards & references

  • RFC 4648 (Base64) — the standard Base64 alphabet and padding this tool produces — A–Z, a–z, 0–9, plus + and /, with = padding.
  • UTF-8 — the text is encoded to UTF-8 bytes before Base64, which is why any Unicode character encodes correctly.

Accuracy & Limitations

Encoding is exact and reversible: decode the output with a Base64 decoder that also reads UTF-8 and you get your original text back, character for character.

It produces standard Base64, not the URL-safe variant. Standard Base64 uses + and /, which have special meaning in URLs; if you need to drop the string into a URL, swap + for - and / for _ yourself (and you may strip the = padding).

Base64 is encoding, not encryption. It scrambles nothing and hides nothing — anyone can decode it. Never use it to protect passwords or secrets; it is for safe transport, not security.

Expect the output to be roughly a third bigger than your text, because every three bytes become four characters. That overhead is the cost of representing data as plain ASCII.

Real-World Use Cases

Embed a token or key

Encode a value so it travels as plain ASCII in a config or header.

Build a data URI

Base64 a small snippet to inline in HTML, CSS, or a data URL.

Move text safely

Pass text through a channel that would otherwise mangle special characters.

Encode Unicode

Base64 text with emoji or non-Latin scripts without the usual errors.

When to use it — and when not to

Good for

  • Encoding text (including Unicode) to Base64
  • Embedding values in configs, headers, or URIs
  • Moving text through ASCII-only channels
  • A quick, exact, reversible transform

Not the best choice for

  • Hiding or securing secrets (it is not encryption)
  • URL parameters without swapping + / for - _
  • Encoding image or binary files (use a file tool)
  • Shrinking data (Base64 grows it ~33%)

For an image or file, use Image to Base64 (it builds a data URI); for a URL, swap to the URL-safe characters; to protect a secret, use real encryption.

Frequently Asked Questions

Does it handle emoji and non-English text?
Yes. It encodes your text as UTF-8 first, so emoji, accented letters, and non-Latin scripts all encode correctly — unlike basic Base64 tools that only handle plain ASCII.
Is Base64 a form of encryption?
No. It is an encoding, fully reversible by anyone with a decoder. It hides nothing, so never use it to secure passwords or sensitive data — use real encryption for that.
Why is the encoded text longer than my input?
Base64 represents every three bytes as four characters, so the output is about 33% larger. That overhead is the price of turning data into plain ASCII.
Can I put the output straight into a URL?
Not always safely. Standard Base64 uses + and /, which are special in URLs. For a URL, replace + with - and / with _ (the URL-safe variant), and you can usually drop the = padding.
What alphabet does it use?
Standard Base64 from RFC 4648: the letters A–Z and a–z, the digits 0–9, plus + and /, with = used as padding at the end.
Can I encode an image or file here?
This tool is for text. To encode an image into a Base64 data URI, use the Image to Base64 tool, which reads the file's bytes directly.
Is my text uploaded?
No. Encoding happens entirely in your browser. Nothing is sent to a server, and clearing the box removes it.
How do I get my text back?
Run the Base64 through a decoder that also handles UTF-8 — like our Base64 Decoder. You will get the exact original text.
Does it add line breaks?
No. It produces a single continuous Base64 string with no inserted newlines, so it is ready to paste as one value.
Is there a length limit?
No fixed limit. It encodes in your browser, so very large text depends on your device, but ordinary strings encode instantly.

References

Built on what the tool truly does — UTF-8 then standard Base64 — and honest that Base64 is encoding for transport, never encryption.

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