Base64 Encoder / Decoder

Encode any text or file to Base64 instantly — or decode a Base64 string back to plain text. Supports URL-safe mode (Base64URL) for JWT tokens and web APIs, MIME line wrap for email attachments, per-line encoding for batch entries, and 8 character sets for legacy systems. Upload a file or image and get the full Base64 and data URI output immediately. Everything runs in your browser — nothing is ever sent to our servers.

Charset:

URL-safe (Base64URL) 76-char MIME wrap Encode each line

0 characters 0 bytes

Base64 Output

Output will appear here…

0 characters output

📁 Encode a File to Base64

Drag & drop a file here, or click to browse

All file types supported · Processed 100% in your browser

Image Preview

File Base64 Output

data: URI (paste directly into HTML/CSS)

Files and text are processed locally in your browser — nothing is uploaded to our servers.

How to Use the Base64 Encoder / Decoder

Choose Encode or Decode

Click the Encode tab to convert plain text or a file into Base64 output. Click Decode to convert a Base64 string back into readable text. The tool switches instantly with no page reload.

Paste Your Text and Set Options

Type or paste your content into the input area — the output updates live as you type. Use the options bar to select your character set, enable URL-safe mode for JWT tokens and web URLs, toggle 76-char MIME wrap for email attachments, or enable Encode each line for batch encoding of multiple values.

Copy, Swap, or Upload a File

Click Copy Output to send the result to your clipboard. Use Swap to push the output back into the input for round-trip testing. To encode a file, drag it into the file upload zone — images will show a live preview and generate a ready-to-use data: URI for embedding directly into HTML or CSS.

Check Validity When Decoding

In Decode mode, a validity badge appears immediately next to your input showing whether the string is valid Base64. If it's invalid, the badge shows red — no guessing required. The decoder automatically handles both standard Base64 (+/) and URL-safe Base64URL (-_) formats.

Frequently Asked Questions

What is Base64 encoding?

What is URL-safe Base64 (Base64URL)?

Why does Base64 increase file size by 33%?

What is MIME line wrap and when do I need it?

What does "encode each line separately" do?

Is my data sent to your server?

What character sets are supported?

Base64 Encoder / Decoder

How to Use the Base64 Encoder / Decoder

Frequently Asked Questions

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