Base64 Encoder / Decoder

What is Base64 Encoding?

Base64 is a binary-to-text encoding scheme that represents binary data using a set of 64 ASCII characters (A–Z, a–z, 0–9, +, and /, plus = for padding). It was originally designed to transmit binary content over channels that only support text, such as email (MIME) and early HTTP. Today Base64 is used everywhere in web development — from embedding images directly in HTML and CSS via data URIs, to encoding authentication tokens, to passing binary payloads through JSON APIs that only accept string values.

How to Use This Tool

1. Select a mode: click Encode to convert plain text into Base64, or Decode to convert a Base64 string back to readable text.
2. Paste or type your content into the left Input panel.
3. Click the Encode to Base64 (or Decode from Base64) button.
4. The result appears instantly in the right Output panel.
5. Use the Copy button to copy the result to your clipboard for use in code, configuration files, or API requests.

When to Use Base64 Encoding

Base64 is the right choice when you need to embed a small image or font directly inside a stylesheet to reduce HTTP requests, when you are constructing a data: URI, or when an API requires you to submit file content as a JSON string. It is also commonly used to inspect or debug encoded values you encounter in JWTs, email headers, or URL parameters.

Tips and Best Practices

• Base64 is not encryption. It provides no security whatsoever — anyone can decode it instantly. Never use it as a way to hide sensitive data.
• Encoding increases size by roughly 33 %. For large files, sending the binary directly (e.g., via multipart/form-data) is far more efficient than Base64-encoding it into JSON.
• This tool on utilsnow.com fully supports UTF-8, so accented characters, CJK text, and emojis encode and decode correctly.
• When embedding Base64 in CSS, use the format url(data:image/png;base64,...) and keep the encoded asset under a few kilobytes to avoid slowing down stylesheet parsing.
• If a Base64 string looks corrupted after decoding, make sure no extra whitespace or line breaks were introduced during copy-paste — Base64 strings must be continuous.