Base64 is a binary-to-text encoding standard (RFC 4648) that represents binary data using 64 ASCII printable characters (A-Z, a-z, 0-9, +, /). It's used to transmit or store binary data in systems that only accept text (like JSON APIs, emails, and XML). The encoding increases data size by approximately 33% but ensures universal compatibility across all platforms and systems.

Standard (RFC 4648): Uses A-Z, a-z, 0-9, +, / with optional padding (=). URL-Safe: Replaces + with - and / with _ to safely use in URLs and query parameters. MIME: Standard Base64 with line breaks every 76 characters, required for email standards. Padding: The = sign aligns the output to 4-character boundaries. RFC 4648 recommends padding, but it's not always required for decoding.

Common Use Cases: (1) Embed binary files in JSON/XML APIs, (2) Convert images to data URIs for inline HTML embedding, (3) Encode credentials for Basic HTTP Authentication, (4) Store binary large objects (BLOBs) in databases, (5) Embed fonts/media files in CSS, (6) Encode OAuth tokens and API credentials, (7) Create data URIs for embedding SVG graphics, (8) Transmit file attachments in email protocols.

Yes! Upload any image file (PNG, JPG, GIF, WebP, SVG) and this tool will instantly generate a data URI. Use the output directly in HTML: <img src="data:image/png;base64,..."> or in CSS background-image properties. Data URIs eliminate separate HTTP requests, improving page load performance for small images. Perfect for embedding logos, icons, and single-pixel tracking images.

Absolutely not. 100% of encoding/decoding happens locally in your browser using JavaScript. Your data never leaves your device - we don't log, store, or transmit anything. Works completely offline after the page loads. Perfect for encoding sensitive API keys, authentication tokens, cryptographic keys, or proprietary data.

Standard Base64 uses + and / which are special characters in URLs and must be percent-encoded (to %2B and %2F). URL-Safe Base64 replaces + with - (minus) and / with _ (underscore) to avoid encoding. Use Standard for JSON APIs, MIME emails, and databases. Use URL-Safe for API tokens, OAuth signatures, JWT tokens, and query parameters - it's RFC 4648 Section 5 compliant.

MIME (Multipurpose Internet Mail Extensions) Base64 adds line breaks every 76 characters. This is required by email standards (RFC 2045) for transmitting binary data in email bodies and attachments. MIME encoding prevents line-length restrictions in mail systems. Use Standard for APIs and MIME for email protocols and legacy systems with line-length limits.

Any file type - images (PNG, JPG, GIF, WebP, SVG, BMP), documents (PDF, DOCX, XLSX, PPTX), archives (ZIP, RAR, 7Z), video/audio (MP4, MP3, WAV), executables, or any binary file. The tool detects the MIME type automatically for data URI generation. File size limit is browser-dependent (typically 2GB+), but processing huge files may be slow.

Paste or input valid Base64 and click "Download as File". The tool detects the file type from the data and generates the proper MIME type header. Your browser automatically downloads the reconstructed file with the original extension. Works with any file format - the same image/document/archive you encoded will be perfectly reconstructed.

Yes! Click the "Batch Mode" button to switch to line-by-line processing. Enter one Base64 string per line, and the tool converts each line independently. Perfect for processing lists of encoded credentials, API tokens, or other Base64 data. Each line is converted separately, output appears line-by-line matching the input structure.

Ctrl+Enter (Cmd+Enter on Mac): Encode the input. Ctrl+D (Cmd+D): Decode the input. Ctrl+C (Cmd+C): Copy the output. Ctrl+Shift+C (Cmd+Shift+C): Clear all text fields. These shortcuts work when the cursor is in an input field.

Absolutely! Fully responsive design works seamlessly on phones, tablets, and desktops. Touch-friendly buttons, readable fonts, and adaptive layouts. File upload works on mobile (choose from photo library or files). Real-time stats display calculations instantly. Perfect for encoding/decoding on the go.

100% accurate - uses native JavaScript Base64 functions (btoa/atob) and RFC 4648 compliant algorithms. Every character is preserved exactly. The tool validates input before encoding and detects invalid Base64 characters during decoding. The real-time stats show exact character and size metrics.

The tool displays a clear error message indicating which characters are invalid. Base64 should only contain A-Z, a-z, 0-9, +, /, and = (for padding). Invalid characters are highlighted. The status bar shows exactly what went wrong, helping you fix the input.

The tool saves your last-used encoding mode in browser local storage. When you return, your preferred settings remain. Copy buttons let you save output to clipboard. For persistent storage, export the result to a file using the "Download as File" button.

Text input has a 6,000 character practical limit to ensure browser responsiveness. File uploads depend on browser memory (typically 100MB-2GB). For very large files, consider breaking them into chunks. Processing time is near-instant even on slower connections.

All modern browsers: Chrome 90+, Firefox 88+, Safari 14+, Edge 90+. Works on Android and iOS mobile browsers. Requires JavaScript enabled. The tool uses standard Web APIs (FileReader, Blob, Clipboard) supported across all modern platforms.

Yes! Perfect for development, testing, and production. Uses RFC 4648 standard algorithms. Client-side processing means zero latency, 100% uptime, and zero data exposure. Many DevOps engineers use it for production deployment config generation, API token encoding, and authentication setup.