Why use Base64 encoding?

Base64 ensures binary data can be safely transmitted over text-based protocols like email or HTTP. It prevents corruption of special characters and preserves data integrity.

Does Base64 increase data size?

Yes, Base64 encoding increases data size by approximately 33%. Every 3 bytes of input become 4 bytes of Base64 output.

Is Base64 encryption?

No, Base64 is encoding, not encryption. Anyone can decode Base64 data. It provides no security—only a different representation of the same data.

Can I encode images to Base64?

Yes! Images can be converted to Base64 strings and embedded directly in HTML, CSS, or JSON. This is useful for small images to reduce HTTP requests.

Base64 Encoder – Encode Base64 Online (Free Tool)

Free online Base64 Encoder tool to encode text, strings, and data to Base64 format instantly. Convert binary data and text to ASCII-safe Base64 encoding for safe transmission over text-based protocols. Perfect for encoding images, credentials, and binary data. All encoding happens locally in your browser ensuring complete privacy.

What is Base64 Encoder?

Base64 Encoder turns arbitrary bytes — text, images, or binary blobs — into an ASCII-safe string that survives transport channels that only accept printable characters. It is the same encoding used by HTTP Basic Auth headers, JWT payloads, and inline data: URLs. The conversion runs entirely in your browser, so secrets you paste never reach a server.

Why use this tool?

No registration, account, or installation required
No API keys to manage and no rate limits to monitor
100% free with no hidden costs or daily limits
Works with very large inputs (multi-megabyte JSON, long regex patterns, big tables)
No telemetry on the tokens, payloads, or code you paste in

How to use

Paste your input into the base64 encoder area
Configure the options if the defaults don't match your case
Click the action button and inspect the result
Copy the output to your clipboard or download as a file

Examples

Encode credentials for Basic Auth

Encode "user:p@ss" to "dXNlcjpwQHNz". The resulting string is what goes after "Authorization: Basic " in an HTTP request.

Inline an SVG icon

Encode the SVG markup to Base64 and use it as `url("data:image/svg+xml;base64,...")` in CSS to remove an HTTP request.

Round-trip a binary buffer

Encode raw bytes here, ship the string in JSON, decode on the other side with the Base64 Decoder tool to get the original buffer back.

Common use cases

Embedding small images and fonts in CSS / HTML to cut requests
Building HTTP Basic Auth headers by hand
Encoding API keys before sending them in JSON
Preparing payloads for JWT or webhook signatures
Storing binary blobs in databases that only accept text

Troubleshooting

Decoded result has mojibake / question marks.: The input was treated as a different encoding. UTF-8 text encodes safely; if you started from a Latin-1 source, convert to UTF-8 first.
Output is ~33% larger than input.: That overhead is intrinsic to Base64 — 3 bytes in, 4 characters out. If size matters, consider Base85 or gzip + Base64 instead.
I get padding-error when decoding elsewhere.: Some libraries reject inputs whose length is not a multiple of 4. Re-add trailing "=" padding characters or switch to a URL-safe variant.

Frequently Asked Questions

Base64 is a binary-to-text encoding scheme that converts binary data into an ASCII string format. It is commonly used to encode data for safe transmission over media designed to handle text.

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