Base64 Encoder/Decoder — Instant, Private, Free

Encode and decode Base64 strings in your browser. Zero server calls, zero tracking.

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📖 How to Use This Base64 Tool

  1. Paste your text — Type or paste any string into the Input box
  2. Click Encode or Decode — Encode converts text→Base64; Decode converts Base64→text
  3. Copy or Share — Click Copy to clipboard, or Share to generate a link with your input pre-filled
  4. Use Swap — Quickly move output back to input for chained operations

❓ Frequently Asked Questions

What is Base64 encoding used for?

Base64 encoding transmits binary data over text-based protocols. Common uses: embedding images in HTML/CSS (data URIs), encoding email attachments (MIME), storing binary data in JSON/XML, and encoding JWT tokens.

Is my data sent to any server?

No. Everything runs in your browser using JavaScript's native btoa() and atob() functions. Open DevTools → Network tab to verify: zero requests are made.

Why does Base64 output look longer than the input?

Base64 uses 4 characters to represent every 3 bytes, resulting in ~33% size increase. This is the trade-off for converting binary data into text-safe ASCII characters.

What's the difference between Base64 and URL encoding?

Base64 converts binary to ASCII text (64 chars). URL encoding replaces unsafe characters with %XX hex. They solve different problems: Base64 for data transport, URL encoding for safe URLs. Try our URL Encoder for percent-encoding.

Can I decode JWT tokens with this?

JWT tokens have 3 Base64URL-encoded parts separated by dots. You can paste the header or payload part here to decode it. For full JWT parsing, try our JWT Decoder.

Can I share my encoded result?

Yes! Click the 🔗 Share button to generate a URL containing your input. Anyone opening the link sees the same data pre-filled — no account needed.

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