What is Base64 encoding?

Base64 is a binary-to-text encoding scheme that represents binary data using 64 printable ASCII characters (A–Z, a–z, 0–9, +, /). It is commonly used to encode binary data (like images or files) for transmission over text-only protocols such as email or embedding in JSON, HTML, and CSS.

Is my data safe when using this tool?

Yes, completely. All encoding and decoding is performed entirely in your browser using JavaScript. No data is ever transmitted to any server. Your text is private and stays on your device.

What is URL-safe Base64?

URL-safe Base64 (RFC 4648 Section 5) replaces the + character with - and / with _, making the output safe to use directly in URLs, query parameters, and filenames without percent-encoding. This tool supports both standard and URL-safe variants.

Can Base64 be used for encryption?

No. Base64 is an encoding scheme, not an encryption algorithm. It simply converts data to a different representation — the original data can be fully recovered by anyone who decodes it. Do not use Base64 to hide sensitive information.

Why does Base64 output end with == or =?

Base64 encodes data in groups of 3 bytes (24 bits) into 4 characters. If the input length is not a multiple of 3, padding characters (=) are added to make the output length a multiple of 4. One = means 1 byte of padding was added, == means 2 bytes.

What characters are valid in a Base64 string?

Standard Base64 uses A–Z, a–z, 0–9, +, and /. URL-safe Base64 replaces + with - and / with _. Both variants may end with one or two = padding characters. Any other character in the input indicates an invalid Base64 string.

Free & Instant

Encode & Decode
Base64 Instantly

Transform any text, URL, JSON, or data to Base64 format and back. No server, no login, no limits — all processing happens right in your browser.

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100% Client-Side

All encoding and decoding happens in your browser. Your data never leaves your device.

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Live Preview

See the result instantly as you type — no need to click a button or wait for anything.

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URL-Safe Mode

Switch to URL-safe Base64 (RFC 4648) that replaces + and / with - and _ for use in URLs.

URL-safe Base64

Text to encode

Base64 output

Output will appear here…

Standard: uses + and /URL-safe: uses - and _ (RFC 4648 §5)Privacy: 100% client-side — data never leaves your browser

Frequently Asked Questions

Everything you need to know about Base64 Encoder.

Encode & DecodeBase64 Instantly

100% Client-Side

Live Preview

URL-Safe Mode

Frequently Asked Questions

Encode & Decode
Base64 Instantly