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Base64 Encoder / Decoder

Encode and decode Base64 strings instantly

Base64 Encoder / Decoder is a free online tool from BrowserUtils that encode and decode base64 strings instantly. It runs entirely in your browser — your data never leaves your device. No account required.

How to use Base64 Encoder / Decoder

  1. 1 Paste or type your input into the editor above.
  2. 2 The tool processes your data instantly — right in your browser, with nothing sent to a server.
  3. 3 Copy the result with one click or continue editing your input.

About Base64 Encoder / Decoder

Free online Base64 encoder and decoder. Convert text to Base64 encoding or decode Base64 strings back to plain text. This tool runs entirely in your browser — your data is never sent to a server. Just paste your input, get instant results, and copy with one click. No sign-up or installation required.

Base64 Encoder / Decoder specs

Runtime
100% client-side (browser)
Built on
TextEncoder, TextDecoder, btoa/atob, and encodeURIComponent — all Web Platform APIs
Cost
Free — no account, no rate limits, no usage caps
Browser support
Chrome 90+, Firefox 88+, Safari 14+, Edge 90+
Part of
299 developer tools on BrowserUtils (100% client-side)

Questions

What is Base64 encoding?
Base64 is a binary-to-text encoding scheme that represents binary data as ASCII characters. It is commonly used to embed data in URLs, emails, and HTML.
Is it safe to decode Base64 online?
Yes, this tool runs entirely in your browser. Your data is never sent to a server.
Why does Base64 make data larger?
Base64 encodes 3 bytes of data as 4 ASCII characters, resulting in roughly 33% size increase. This tradeoff allows binary data to be safely transmitted in text-only contexts.
Can I Base64 encode an image?
Yes, you can encode binary file data as Base64. For images, use the Image to Base64 tool which handles file upload and produces a ready-to-use data URI.
Does this Base64 tool work offline?
Yes, encoding and decoding happen entirely in your browser using JavaScript. No internet connection is needed after the page loads.
What is the difference between Base64 and Base64URL encoding?
Standard Base64 uses + and / as extra characters, while Base64URL replaces them with - and _ to make the output safe for use in URLs and filenames without additional percent-encoding.
Embed this tool

Copy this code to embed the tool on your website. Adjust the height to fit your layout.

<iframe src="https://www.browserutils.dev/embed/base64-encode-decode" width="100%" height="500" frameborder="0" title="Base64 Encoder / Decoder"></iframe>

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