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Bidirectional Conversion

Decode Base64 strings to text/binary or encode text/files to Base64 format. Single tool handles both operations with instant mode switching, perfect for developers working with Base64 encoding in APIs, databases, or data transmission.

Image Decode & Preview

Automatically detect and decode Base64-encoded images with instant preview. Supports PNG, JPEG, GIF, SVG, and WebP. Perfect for extracting images from API responses, JSON data, or HTML data URIs for inspection or downloading.

Multiple Encodings

Support for UTF-8, UTF-16, ASCII, and Latin-1 character encodings ensures accurate decoding of international characters, emojis, and special symbols. Choose the right encoding to match your data source for perfect character interpretation.

Auto-Detection

Intelligent auto-detection identifies data types including text, images, PDFs, and binary files. Automatically strips whitespace and handles different Base64 formats (standard, URL-safe, MIME) for hassle-free decoding without format guessing.

File Upload Support

Upload files directly for Base64 encoding instead of copying text manually. Perfect for encoding images, documents, PDFs, or any file type for embedding in HTML, JSON, or transmitting via text-based protocols without binary support.

Real-Time Conversion

Auto-convert feature processes Base64 strings instantly as you type with no delays. All processing happens client-side in your browser for maximum speed and complete privacy. No server uploads means your data stays secure.

Base64 Encoded Size:

Encoded Length = ⌈(n / 3)⌉ × 4

where n = number of input bytes, ⌈⌉ = ceiling function

📧 Email Attachments

Email systems were designed for text, not binary data. MIME (Multipurpose Internet Mail Extensions) uses Base64 to encode file attachments for safe transmission. Decode Base64 strings from email source code or encode files for embedding in email systems and templates.

🔌 API Data Transfer

REST APIs and JSON responses use Base64 to transmit binary data like images, PDFs, or files without special handling. Decode Base64 from API responses to extract files or encode binary data for POST/PUT requests in web services and microservices architectures.

🗄️ Database Storage

Store binary files in text-based database fields using Base64. Common in NoSQL databases like MongoDB or when storing small images, documents, or certificates in SQL VARCHAR/TEXT columns. Decode stored Base64 strings to retrieve original files.

🌐 Data URIs in HTML

Embed images directly in HTML/CSS using data URIs (data:image/png;base64,...) to reduce HTTP requests. Decode data URIs to extract embedded images or encode images for inline embedding in single-page applications, email templates, or offline HTML documents.

🔐 Authentication Tokens

HTTP Basic Authentication encodes credentials as Base64 in the Authorization header. JWT (JSON Web Tokens) use Base64URL encoding for token components. Decode authentication headers for debugging or testing, though remember Base64 is encoding, not encryption.

📄 Configuration Files

Store binary configuration data, certificates, or keys in text-based config files (JSON, YAML, XML) using Base64. Kubernetes secrets, SSL certificates, and encryption keys are commonly Base64-encoded in configuration management for text-based storage and version control systems.

Paste your Base64 string into the input field, select "Decode" mode, and the tool automatically converts it to readable text. Base64 decoding reverses the encoding process by converting each group of 4 Base64 characters back to 3 bytes of original data. The decoded text appears instantly with auto-convert enabled. For best results, ensure you select the correct character encoding (UTF-8 for most cases) that matches how the data was originally encoded.

Base64 is encoding, NOT encryption. Encoding transforms data format (binary to text) for compatibility, while encryption secures data with cryptographic algorithms. Anyone can decode Base64 instantly without keys or passwords—there's no security. Base64 makes data unreadable to humans but provides zero protection from automated decoding. For security, use proper encryption like AES, RSA, or other cryptographic methods before Base64 encoding if needed for text transmission.

Base64 increases data size by approximately 33% because it converts 3 bytes (24 bits) of binary data into 4 Base64 characters (32 bits). Each Base64 character represents only 6 bits of data instead of 8 bits per byte. This "wasted" space is the tradeoff for text compatibility. The extra 33% is acceptable for small data but can be significant for large files. Always compress data before Base64 encoding when size matters, or use binary transfer methods when possible.

The equals sign (=) is padding that ensures Base64 strings are always multiples of 4 characters long. When input data length isn't divisible by 3, padding is added: one = if one byte short, two == if two bytes short. Padding tells decoders where actual data ends and padding begins. Some Base64 variants (like URL-safe) omit padding for brevity, but standard Base64 includes it. Decoders can often work with or without padding, but including it follows the official specification.

Yes! Our tool automatically detects and decodes Base64-encoded images including PNG, JPEG, GIF, SVG, and WebP formats. When you paste a Base64 image string (or data URI like data:image/png;base64,...), the tool decodes the binary image data and displays a preview. You can then download the decoded image as a file. This is useful for extracting images from API responses, JSON data, HTML source code, or email attachments that use Base64 encoding.

Standard Base64 uses + and / characters which have special meanings in URLs (+ becomes space, / is path separator). Base64URL is a URL-safe variant that replaces + with - (minus) and / with _ (underscore), making encoded strings safe for URLs, filenames, and cookies without escaping. Base64URL often omits padding (=) for brevity. JWT tokens use Base64URL encoding. Our tool supports both formats automatically, detecting and converting between them transparently during decode/encode operations.