Base64 Encoder / Decoder

Encode text to Base64 or decode it back — instantly and privately in your browser.

ToolFlux's Base64 Encoder / Decoder converts text to Base64 and back with one click — it is UTF-8 and emoji safe, runs entirely in your browser, and never uploads your data. Remember: Base64 is encoding, not encryption.

Your text never leaves your device — encoding and decoding run in your browser.

Encode and decode Base64 online, instantly and privately

This free Base64 encoder and decoder converts text to Base64 and back with a single click. Paste any text to turn it into a compact, text-safe Base64 string, or paste a Base64 value to recover the original text. Everything happens in your browser, so even sensitive strings never leave your computer — there is nothing to install and no account to create. The tool is fully UTF-8 aware, which means accented letters, emoji and non-Latin scripts round-trip perfectly rather than being corrupted.

How to encode or decode Base64

  1. Paste your input Type or paste your plain text (to encode) or a Base64 string (to decode) into the input box.
  2. Choose a direction Click “Encode to Base64” to convert text into Base64, or “Decode from Base64” to turn Base64 back into text.
  3. Read the result The converted value appears instantly in the result box below. If the Base64 is invalid, a clear message tells you.
  4. Copy it Press Copy result to copy the output to your clipboard, then paste it wherever you need it.

What is Base64 and when do you use it?

Base64 is a way of representing binary data — or any text — using only 64 printable ASCII characters. It exists because many systems were designed to carry text, not raw bytes, and will mangle or reject characters they do not expect. By re-expressing data in a safe, limited alphabet, Base64 lets you move binary content through text-only channels untouched.

You will most often meet Base64 in these situations:

  • Data URIs. Small images, icons and fonts can be embedded directly in CSS or HTML as data:image/png;base64,…, saving an extra network request.
  • JSON and web APIs. Binary payloads such as file contents or signatures are Base64-encoded so they can travel inside a JSON string field.
  • Email attachments. The MIME standard encodes attachments in Base64 so they survive mail servers that only handle plain text.
  • Tokens and headers. Values such as JWT segments and HTTP Basic Auth credentials are Base64 (or URL-safe Base64) encoded for safe transport.

Base64 is encoding, not encryption

This is the single most important thing to understand about Base64: it offers no security at all. Encoding simply rearranges data into a different representation, and anyone can reverse it instantly — including this very tool. Seeing an unreadable jumble of letters can create a false sense of safety, but a Base64 string is effectively plain text. Never use Base64 to protect passwords, API keys, personal data or any other secret. If you need genuine confidentiality, use real encryption such as AES, and keep the keys safe. Base64 is for transport, not for hiding things.

Standard versus URL-safe Base64

Standard Base64 includes the characters + and /, which have special meanings inside URLs. To avoid escaping, a URL-safe variant replaces them with - and _ and often drops the = padding. This decoder accepts both: it automatically normalises URL-safe input and restores any missing padding, so you can paste a value straight from a URL, a JWT or a config file without cleaning it up first.

Frequently asked questions

Is Base64 encryption?
No. Base64 is a reversible encoding, not encryption. Anyone can decode it back to the original text in seconds — it provides no security or confidentiality whatsoever. Never use it to “hide” passwords, tokens or secrets.
Are my text and files uploaded anywhere?
No. Encoding and decoding run entirely in your browser using built-in JavaScript. Nothing is sent to a server, so even sensitive strings never leave your device.
Why is the Base64 output bigger than the original?
Base64 represents every three bytes of data using four printable characters, so the encoded output is roughly 33% larger than the original. That overhead is the price of making binary data safe to embed in text-only formats.
What characters does Base64 use?
Standard Base64 uses the 64 characters A–Z, a–z, 0–9, plus “+” and “/”, with “=” for padding. The URL-safe variant swaps “+” and “/” for “-” and “_” so the value can be dropped into a URL without escaping. This tool decodes both.
Can I decode a data URI with this tool?
You can decode the Base64 portion. A data URI looks like “data:image/png;base64,iVBOR…”. Copy only the part after “base64,” into the input and decode that — the prefix before the comma is metadata, not Base64 data.
Does it work offline?
Yes. Once the page has loaded, no connection is needed. The conversion happens locally in your browser, so you can encode and decode even with no internet at all.