HIFreeTools

Free Base64 Encoder & Decoder

Convert text to Base64 and back. Works with full Unicode via UTF-8, and runs entirely in your browser so nothing is uploaded.

Quick answer

Base64 is a way to represent binary data using 64 printable ASCII characters. It maps every 3 bytes of input to 4 output characters, padding the end with “=” when needed. It is an encoding, not encryption — anyone can decode it.

Formula & method

Text is first converted to bytes using UTF-8, then those bytes are grouped three at a time and mapped to four characters from the Base64 alphabet (A–Z, a–z, 0–9, + and /). Decoding reverses the process. The tool handles Unicode correctly, so emoji and accented characters round-trip without corruption.

Examples

Example 1: Encode a word
Input
Hello
Result
SGVsbG8=
Why
Five bytes encode to eight Base64 characters, including one “=” pad.
Example 2: Encode with padding
Input
Hi
Result
SGk=
Why
Two bytes need padding to complete the final group of four.
Example 3: Decode
Input
d29ybGQ=
Result
world
Why
Decoding turns the Base64 text back into the original string.

When to use this tool

  • Inspecting a Base64 string from a token, data URI, or config file.
  • Embedding small data inline where only text is allowed.
  • Quickly decoding a Base64 value to read what it contains.

Common mistakes

  • Treating Base64 as encryption. It only obscures data; it provides no security.
  • Forgetting that Base64 grows the size by about one third.
  • Mixing up standard Base64 (with + and /) and URL-safe Base64 (with - and _).

Frequently asked questions

＋ What is Base64 used for?

It encodes binary or text data as plain ASCII so it can travel safely through systems that expect text, such as data URIs, email attachments, and some tokens.

＋ Is Base64 encryption?

No. It’s a reversible encoding with no key, so anyone can decode it. Never use it to protect secrets.

＋ Why are there “=” signs at the end?

They’re padding. Base64 works in groups of four characters, so “=” fills out the final group when the input length isn’t a multiple of three bytes.

＋ Does it handle emoji and accents?

Yes. The tool encodes text as UTF-8 first, so Unicode characters encode and decode correctly.

＋ Is my input uploaded?

No. Encoding and decoding happen entirely in your browser.

  • ✓ Free to use
  • ✓ No sign-up required
  • ✓ Runs entirely in your browser — nothing is uploaded.
  • ✓ Formula and method shown above
Last updated: How we calculateReport a correctionDisclaimer

Provided “as is” for general information only — results may be inaccurate, so verify before you rely on them. No warranty; use at your own risk.

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