Base64 Encode / Decode

Base64 Encode and Decode Online

Base64 is a binary-to-text encoding scheme that represents binary data using 64 printable ASCII characters. It is widely used in protocols that do not support raw binary data.

Common Uses of Base64

• encoding email attachments (MIME);
• embedding images in CSS / HTML (data:image/png;base64,...);
• JWT tokens use URL-safe Base64 for the header and payload;
• HTTP Basic Auth: Authorization: Basic base64(user:pass).

URL-safe Base64 replaces + with - and / with _, making the string safe for use in URLs without additional percent-encoding.

Frequently Asked Questions

• What is the difference between standard Base64 and the URL-safe variant?

  Standard Base64 uses the characters + and /, which can cause issues in URLs (+ is interpreted as a space, / splits path segments). URL-safe Base64 replaces + with - and / with _, and typically omits the = padding. Our tool supports both modes, making it easy to work with JWT tokens and API query parameters.

• Can I encode an image or file to Base64 with this tool?

  Yes, the tool on 101ip.ru/base64/ supports file uploads. Select any image, document or archive from your computer and the service will convert its contents to a Base64 string automatically. The reverse also works — paste a Base64 string to decode it and download the original file. This is useful for embedding images directly into HTML or CSS.

• Why does an encoded string sometimes end with = or ==, and how do I remove it?

  The = characters (one or two) are appended by the algorithm to align the output length to a multiple of 4. They are required for correct decoding in strict implementations. To get a string without them, switch to URL-safe mode (which omits padding automatically) or simply trim the = characters — most decoders handle padding-free input correctly.