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Base64 Encoder & Decoder — Free Online Tool

Encode and decode Base64, URL, Hex, Binary, ROT13, Morse Code, ASCII & HTML Entities — supports text, images, and files. Instant, free, and 100% private.

✓ 100% Free✓ No Signup✓ Private & Secure✓ Works Offline✓ 8 Encoding Modes✓ Image Support✓ File Support
Standard Base64 encoding (RFC 4648)
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Quick Encode Samples

Free Online Base64 Encoder and Decoder

Utilsly's Base64 Encoder/Decoder is a free, browser-based tool that instantly encodes or decodes text, images, and files using Base64 and 7 other popular encoding formats. Everything runs locally in your browser — your data is never sent to any server.

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, +, /). Defined in RFC 4648, it is widely used to safely transmit binary data over text-based channels such as email, HTTP headers, and JSON APIs. Base64 increases data size by approximately 33% due to its 3-bytes-to-4-characters mapping.

Supported Encoding Formats

  • Base64 — Standard Base64 (RFC 4648). Used in JWT, data URIs, MIME, HTTP Basic Auth.
  • URL Encode — Percent-encoding (RFC 3986). Used in query strings and form submissions.
  • Hex — Hexadecimal encoding of UTF-8 bytes. Used in cryptography and color codes.
  • Binary — 8-bit binary representation of every character.
  • ROT13 — Simple symmetric Caesar cipher shifting letters by 13 positions.
  • Morse Code — International Morse code encoding of text.
  • ASCII Codes — Decimal ASCII code point for each character.
  • HTML Entities — Encode/decode HTML special characters (&, <, >, etc.).

Common Use Cases for Base64 Encoding

  • JWT Tokens — The header and payload of JSON Web Tokens are Base64URL-encoded.
  • HTTP Basic Authentication — Credentials are Base64-encoded in the Authorization header.
  • Data URIs — Inline images in HTML or CSS use Base64 to embed binary data directly.
  • Email Attachments (MIME) — Email protocols use Base64 to encode binary attachments.
  • API Payloads — Binary data is Base64-encoded for JSON compatibility.

Is My Data Safe When Using This Free Base64 Tool?

Yes. This tool runs entirely in your browser using JavaScript. No data you enter, upload, or encode is ever sent to our servers. You can safely use this tool with passwords, API keys, private files, or any sensitive information. It also works completely offline once the page loads.

Frequently Asked Questions — Base64 Encoder & Decoder