Base64 Encoder / Decoder
Encode text to Base64 or decode Base64 back to text.
Use on any page (bookmarklet)
Want Base64 Encoder / Decoder without leaving the page you're on? Drag the button below to your bookmarks bar, then click it on any website to open Base64 Encoder / Decoder right there — it runs entirely in your browser.
Use responsibly: a bookmarklet runs on whatever page you click it on. Avoid sensitive sites such as online banking, payment, or healthcare pages — you run it at your own risk. Everything is processed locally and no data is sent anywhere. See our Terms.
- Show your bookmarks bar if it's hidden — Ctrl+Shift+B (⌘+Shift+B on Mac).
- Drag the button above onto the bookmarks bar.
- Open any website and click the bookmark — the Base64 Encoder / Decoder panel appears in the top-right corner. Use ✛ to move it between corners, or ›/‹ to tuck it against the edge and pull it back out.
- Click the bookmark again (or the ✕) to close it.
Note: a few sites with strict security policies may block bookmarklets.
Examples
Encode text to Base64
Input
Hello, world!
Output
SGVsbG8sIHdvcmxkIQ==
Decode Base64 to text
Input
UnVuV2ViVG9vbHM=
Output
RunWebTools
URL-safe encoding
Input
subjects?_d=q_v2
Output
c3ViamVjdHM_X2Q9cV92Mg
About this tool
This free online Base64 encoder and decoder converts text to Base64 and back, right in your browser. Switch between Encode and Decode and the result updates live as you type. Everything runs locally with no upload, so your data never leaves your device — safe even for tokens and other sensitive values.
How to use
- Pick Encode (text → Base64) or Decode (Base64 → text).
- Type or paste your input on the left (or click Sample).
- Copy the result, or hit Swap to feed it back and flip direction.
- Toggle URL-safe if you need a result safe for URLs and filenames.
What this tool handles for you
- Full Unicode: text is encoded as UTF-8 first, so emoji and accented or non-Latin characters round-trip perfectly.
- URL-safe mode: swaps
+and/for-and_and drops=padding — the form used in JWTs and query parameters. - Forgiving decode: stray line breaks and whitespace in pasted Base64 are ignored, and both standard and URL-safe input decode.
Common tasks
- Embed a small image in CSS or HTML as a
data:URI to save a request. - Build a Basic Auth header: encode
username:passwordfor anAuthorization: Basicheader. - Read an API payload or a JWT part: decode a Base64 section to inspect its contents (for tokens, the JWT decoder does it in one step).
Good to know
Base64 output is about a third larger than the input, so it's best for small data. And it is an encoding, not encryption — it adds no security, since anyone can decode it. For the full picture of how and why it works, see our guide to Base64 encoding.
Frequently asked questions
Is this Base64 tool free?
Yes — it's a completely free online Base64 encoder and decoder with no sign-up. Encode or decode as much as you like.
Is my data uploaded to a server?
No. Encoding and decoding happen entirely in your browser with no upload, so your data never leaves your device — safe for tokens and private data.
Does it handle emoji and non-English text?
Yes. The tool encodes text as UTF-8 before converting to Base64, so emoji and accented or non-Latin characters round-trip correctly.
What is URL-safe Base64?
URL-safe Base64 replaces + and / with - and _ and drops the trailing = padding, so the result is safe in URLs and filenames. The decoder accepts both standard and URL-safe input.
Is Base64 encryption?
No. Base64 is an encoding, not encryption — it provides no security, only a safe text representation of data. Anyone can decode it.
What is Base64 used for?
Embedding images in CSS or HTML as data URIs, encoding credentials in HTTP headers, and moving binary data through systems that only handle text.
How do I decode a Base64 string?
Switch to Decode, paste the Base64, and the original text appears instantly. Use Swap to flip a result back the other way.
Learn more
Base64 Encoding Explained: What It Is and When to Use It
GuideJWT Explained: Structure, Claims, and How to Decode One
GuideURL Encoding Explained: Percent-Encoding and When You Need It
ReferenceASCII Table: Decimal, Hex, and Character Reference
ReferenceMIME Types Reference: Content Types by File Extension
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