useonlinetools

Base64 encode / decode

free base64 encoder & decoder — right in your browser, no uploads, no sign-up, instant results.

Encoding and decoding runs locally — your data never touches a server.
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how to use

How to use this tool

1

Upload your files

Drop files onto the page or select them from your device. They're read locally — nothing leaves your browser.

2

Configure options

Adjust any settings or preferences for how you want the tool to process your files.

3

Process

Click the action button and the work is done in your browser — no waiting for server uploads or downloads.

4

Download your result

Save the processed file straight to your device. No watermarks, no sign-up, no limits.

about this tool

Free Base64 Encoder & Decoder without giving up your privacy

Base64 encoding is everywhere — from HTTP Basic Auth headers to embedding images in CSS, from JWT tokens to data URIs. But pasting credentials or tokens into a server-side encoder is a security risk. This tool uses the browser's native btoa and atob functions, plus the TextEncoder API for proper UTF-8 support (meaning emojis, accented characters, and non-Latin scripts encode correctly). Your input is processed entirely in your browser tab — the encoded or decoded result appears instantly, and nothing is ever transmitted. It works offline once the page has loaded, so you can use it in secure environments, on planes, or anywhere connectivity is limited.

Privacy by design. This tool loads once and runs entirely in your browser tab. Close the tab and nothing remains. No cookies, no tracking, no server — just the utility you need, instantly.

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faq

Frequently asked questions

No. All processing happens entirely inside your browser. Your files are read locally, processed in your device's memory, and handed back as a download — nothing is transmitted anywhere.
No. There's no sign-up, no email, and no paywall. Open the tool, process your files, and download — that's the entire flow.
No fixed cap. Because everything runs locally, the practical limit is your device's available memory. Most people process files up to hundreds of megabytes without any issue.
Yes. Once the page loads, the entire tool runs in your browser and works without an internet connection — perfect for planes, secure environments, or anywhere with limited connectivity.
No. The tool preserves your files exactly as they are. No quality loss, no compression artifacts, no modification unless you explicitly choose to apply changes.

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