Base64 Encode & Decode

Convert text to Base64 and back — with full UTF-8 support and a URL-safe option — instantly and privately in your browser.

🔒 Runs entirely in your browser — nothing you type is uploaded or stored on a server.

The Base64 tool encodes text to Base64 and decodes it back again. Switch direction with one click: Text → Base64 turns any string into the compact ASCII form used all over the web, and Base64 → Text reverses it. The result updates as you type, ready to copy or download, with clear error messages if the input you paste isn't valid Base64.

Base64 represents binary or text data using only 64 safe ASCII characters, so it can travel through channels that only handle plain text — data URIs, JSON and XML payloads, email attachments (MIME), HTTP headers and JWT tokens. This tool handles full Unicode correctly: it encodes text as UTF-8 first, so emoji and accented letters round-trip perfectly instead of being mangled the way a naïve btoa() would mangle them.

Need the output to sit safely inside a URL or filename? Turn on URL-safe (base64url) and the + and / characters become - and _ with the padding removed — the variant used by JWTs and many APIs. Decoding accepts both standard and URL-safe input automatically. It all runs in your browser, so tokens and private data are never uploaded.

How to use

  1. Pick a direction: “Text → Base64” to encode, or “Base64 → Text” to decode.
  2. Type or paste your input — the result appears instantly below.
  3. Turn on “URL-safe” if the Base64 needs to go into a URL, filename or JWT.
  4. Copy or download the result, or press “Use result as input” to chain a conversion.
  5. If decoding fails, check the error message — it tells you what's wrong with the input.

Examples

Encode text
“Man” becomes “TWFu”; “Hello, 世界 👋” encodes as valid UTF-8 Base64 that decodes back exactly.
Decode a token
Paste the payload segment of a JWT to read the JSON claims inside it.
URL-safe output
Turn on URL-safe to get base64url (- and _ instead of + and /, no padding) for use in links and tokens.
Data URI
Encode a small snippet of text or SVG to embed it directly in a data: URL.

Frequently asked questions

What is Base64 used for?
It encodes data using 64 plain-ASCII characters so binary or text can pass safely through systems built for text — data URIs, JSON/XML payloads, email (MIME), HTTP headers and tokens like JWTs. It's an encoding, not encryption: anyone can decode it.
Does it handle emoji and accented characters?
Yes. Text is encoded as UTF-8 before Base64, so Unicode — emoji, accents, non-Latin scripts — round-trips perfectly. This avoids the corruption you'd get from the browser's raw btoa(), which only handles Latin-1.
What is URL-safe Base64 (base64url)?
A variant that replaces the + and / characters with - and _ and drops the = padding, so the result is safe to put in URLs, filenames and JWTs. Turn on the URL-safe option to produce it; decoding accepts it automatically.
Is Base64 encryption?
No. Base64 is reversible encoding with no key — it provides zero security. Anyone can decode it back to the original. Never use it to protect passwords or secrets; use real encryption for that.
Why did decoding fail?
The input contains characters that aren't valid Base64, or its length is wrong. The tool shows a specific error. Make sure you pasted the complete Base64 string (both standard and URL-safe forms are accepted).
Is my data uploaded?
No. Encoding and decoding run entirely in your browser, so tokens, payloads and private text never leave your device.

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