Base 64 Decoder

Base64 is a binary-to-text encoding scheme that represents binary data (such as images, files, or any byte stream) in an ASCII string format. It is commonly used to transmit data over media that are designed to handle textual data, like email (MIME), HTML, or JSON APIs.

The term “Base64” comes from the fact that it uses a set of 64 characters (A–Z, a–z, 0–9, +, /) to represent binary data in a text-safe format. Padding is added with = characters to maintain alignment.

While Base64 increases the size of the encoded data by about 33%, it ensures compatibility when embedding or transmitting binary content through systems that only support text, such as web APIs, cookies, or HTML documents.

Common Use Cases:

• Embedding images in HTML or CSS: Convert image files to Base64 for inline display in src or background-image attributes.
• Data URIs: Used in emails or documents where images must be embedded directly in the content.
• Storing small files in JSON: Convert binary files (e.g., PDFs or profile pictures) to Base64 for embedding in JSON or form data.
• Encoding authentication data: Used in Basic Auth headers (e.g., Authorization: Basic <base64-credentials>).
• Cross-platform transmission: Ensures binary data remains intact during transport over protocols like HTTP or SMTP.

Base64 is not encryption — it’s an encoding mechanism. It should not be used to secure sensitive data but rather to safely represent it in text-based formats.

A Base64 Decoder converts Base64-encoded strings back into their original form—whether that’s plain text, binary files, or media content. This is essential when working with encoded data embedded in HTML, APIs, or data streams that require decoding before use.

Why Use a Base64 Decoder?

• Restore embedded content: Decode images, fonts, or files that have been encoded for web use or transmission.
• Read API responses: Decode Base64-encoded data received from third-party APIs or cloud services.
• Handle credentials: Decode Basic Auth headers or encoded keys during authentication debugging.
• Extract original files: Decode files embedded in JSON, email attachments (MIME), or scripts.

How to Use the Tool

• Paste your Base64 string into the left editor.
• Click the “Base64 Decode” button between the editors.
• View the decoded output in the right-hand editor instantly.

The decoder handles proper character conversion, padding, and line-break normalization to accurately reconstruct the original input. It’s especially useful for developers debugging web requests, dealing with binary file uploads, or decoding user data in APIs.