What is Base64, in plain words?

Base64 is a way to write any data — text, images, files — using only 64 safe characters (A–Z, a–z, 0–9, + and /). It exists so binary data can travel through systems designed for plain text, like email, JSON, XML or URLs. It makes data roughly 33% larger.

Is Base64 encryption? Is it secure?

No — and this is the most important thing to know. Base64 is encoding, not encryption. Anyone can decode it instantly, with no key or password. Never use Base64 to “hide” passwords or secrets. If you need confidentiality, you need real encryption.

Does this tool handle emoji and non-English text?

Yes. Text is converted to UTF-8 bytes before encoding, which is the standard other systems expect — so emoji, accents, Hindi, Chinese, Arabic and every other script encode and decode correctly. Naive tools that skip this step corrupt anything beyond basic ASCII.

What is URL-safe Base64?

Standard Base64 uses + and /, which have special meanings inside URLs. URL-safe Base64 (RFC 4648 §5) replaces them with - and _ and usually drops the = padding. JWTs use this variant. The tool can produce it when encoding, and accepts both variants automatically when decoding.

Why does my Base64 string fail to decode?

Usual suspects: the string was truncated when copying, extra characters got mixed in, or it isn’t actually Base64. The tool already ignores whitespace and line breaks and restores missing padding for you — so if it still fails, some character in the middle doesn’t belong.

Is anything I paste sent to a server?

No. Encoding and decoding run entirely in your browser — your data never leaves the device, nothing is stored, and the page works offline after loading. Base64 strings often wrap credentials and tokens, so this matters more than it seems.

Why is the encoded text longer than the original?

Base64 stores 3 bytes of data in 4 characters, so output is about 4/3 the input size, plus up to two = padding characters. That overhead is the price of using only text-safe characters — it’s normal and every correct encoder produces it.

Base64 Encoder / Decoder

Encode text to Base64 or decode it back — Unicode-safe, with a URL-safe option, fully offline.

Files never leave your device Instant — no upload waitFree, no sign-up

Direction

Your text

URL-safe output (uses - and _ instead of + and /, no padding)

Base64 encode and decode — Unicode-safe, in your browser

Base64 turns any data into plain, transport-safe text — which is why you meet it everywhere: API credentials, data URLs, email attachments, JWT tokens, config files. This freeBase64 encoder / decoder converts in both directions instantly, handles emoji and every language correctly via UTF-8, and offers the URL-safe variant (- and _ instead of + and /) that JWTs and web APIs expect.

Decoding that doesn’t fight you

Real-world Base64 arrives mangled: wrapped across lines in a config file, padding stripped by some framework, standard and URL-safe alphabets mixed. The decoder ignores whitespace, accepts both alphabets and restores missing padding automatically — paste what you have and it does the cleanup. The “swap” button feeds a result back as input, so round-trip checks take one click.

Nothing leaves your device

Base64 strings very often wrap things that are sensitive by definition — basic-auth headers are literally username:password encoded in Base64. Sending that to some website’s server to “decode online” defeats the point. Here, everything runs locally in your browser: no upload, no logging, and it works offline once loaded.

Encoding ≠ security

One honest warning: Base64 is not encryption. It hides nothing — anyone can decode it in milliseconds, as this very page proves. Treat any Base64-wrapped secret as plain text when you think about where it is safe to store or send.

Related free tools

Decoding a token? Our JWT decoder splits and decodes all three parts and reads the expiry for you. Got JSON out of your decoded string? Clean it up in theJSON formatter. Encoding text for a link instead? You probably want theURL encoder — percent-encoding, not Base64.

Frequently Asked Questions

What is Base64, in plain words?
Base64 is a way to write any data — text, images, files — using only 64 safe characters (A–Z, a–z, 0–9, + and /). It exists so binary data can travel through systems designed for plain text, like email, JSON, XML or URLs. It makes data roughly 33% larger.
Is Base64 encryption? Is it secure?
No — and this is the most important thing to know. Base64 is encoding, not encryption. Anyone can decode it instantly, with no key or password. Never use Base64 to “hide” passwords or secrets. If you need confidentiality, you need real encryption.
Does this tool handle emoji and non-English text?
Yes. Text is converted to UTF-8 bytes before encoding, which is the standard other systems expect — so emoji, accents, Hindi, Chinese, Arabic and every other script encode and decode correctly. Naive tools that skip this step corrupt anything beyond basic ASCII.
What is URL-safe Base64?
Standard Base64 uses + and /, which have special meanings inside URLs. URL-safe Base64 (RFC 4648 §5) replaces them with - and _ and usually drops the = padding. JWTs use this variant. The tool can produce it when encoding, and accepts both variants automatically when decoding.
Why does my Base64 string fail to decode?
Usual suspects: the string was truncated when copying, extra characters got mixed in, or it isn’t actually Base64. The tool already ignores whitespace and line breaks and restores missing padding for you — so if it still fails, some character in the middle doesn’t belong.
Is anything I paste sent to a server?
No. Encoding and decoding run entirely in your browser — your data never leaves the device, nothing is stored, and the page works offline after loading. Base64 strings often wrap credentials and tokens, so this matters more than it seems.
Why is the encoded text longer than the original?
Base64 stores 3 bytes of data in 4 characters, so output is about 4/3 the input size, plus up to two = padding characters. That overhead is the price of using only text-safe characters — it’s normal and every correct encoder produces it.