Free Online Base64 Encode
Turn your text, files, and images into Base64-encoded strings instantly within your browser. This workspace brings together six essential encoding and decoding tools, from standard and URL-safe Base64 to specialized image-to-data-URI and general file converters. Simply paste your text, upload a file, or drag and drop your content to get started. All processing happens locally on your device using native browser APIs like btoa, atob, TextEncoder, and FileReader, ensuring your data never leaves your machine.
Encode
Transform plain text, including emoji and special characters, into standard Base64 using the traditional A-Z, a-z, 0-9, +, / character set.
Decode
Turn encoded strings back into readable UTF-8 text while automatically handling whitespace and complex multibyte characters.
URL Encode
Generate RFC 4648 compliant Base64 strings that replace +, /, and = characters to ensure compatibility with URLs and JWTs.
URL Decode
Restore and decode URL-safe strings by mapping characters back to their standard forms before translating them to plain text.
Image Encode
Generate ready-to-use data URI strings from your images, perfect for direct embedding in HTML or CSS stylesheets.
File Encode
Process any file into a Base64 string with automatic MIME detection and helpful details like file size and original name.
Online Base64 Encode with Text, File, and Image Support
The tool features a split-pane interface where your input sits on the left and results appear on the right. To encode or decode text, just type or paste into the left panel and click the convert button for instant results. A handy status bar keeps you informed about input and output sizes, along with your current encoding mode. When working with files or images, the left panel transforms into a drag-and-drop zone for easy uploads directly from your computer.
Standard and URL-Safe Variants
While standard Base64 uses the A-Z, a-z, 0-9, +, and / character set, the URL-safe variant swaps + for - and / for _, while stripping padding. This makes the output perfect for URLs, JWT tokens, and filenames without needing extra percent-encoding. You can toggle between these two variants with a single click in the workspace.
Upload Files and Images for Encoding
You can upload various formats like PNG, JPG, SVG, and WEBP to the Image Encode tool, which generates a complete data URI ready for use. A live preview helps you verify the image before you copy the code. For other needs, the File Encode tool processes any file type into raw Base64 text. After uploading, you'll see the original file name, size, and MIME type for your reference.
How Base64 Encoding Works
At its core, Base64 encoding represents binary data using a set of 64 printable ASCII characters. Since every three bytes of input are mapped to four output characters, the resulting string is typically about 33% larger than the source. The process works by grouping input bytes into 6-bit chunks and matching them to the Base64 alphabet, using = characters to ensure the final output length is a multiple of four.
Common Uses for Base64
Using data URIs to embed images directly in HTML or CSS is a great way to reduce HTTP requests and speed up page loads. Base64 is also essential for including binary data in JSON or XML payloads where only text is supported. You'll find URL-safe Base64 in every JWT token, while email protocols rely on it for binary attachments. It's also a common choice for storing keys and certificates within configuration files.
UTF-8 and Multibyte Character Handling
The tool utilizes the TextEncoder API to transform your text into UTF-8 bytes before encoding, ensuring full support for emoji, accented characters, and non-Latin scripts. This prevents data loss and ensures that what you decode is exactly what you started with. The decoding process uses TextDecoder to accurately reconstruct the original text from the Base64 string.
Your Data Stays in Your Browser
Your privacy is a priority, so every conversion happens locally in your browser using native APIs like btoa, atob, and FileReader. Text encoding and decoding leverage TextEncoder and TextDecoder, while file processing uses the FileReader API. Data is never transmitted to a server, and the tool requires no account or cookies to function. Once you close the tab, your information is completely cleared from memory.
Related Base64 and Encoding Tools
If you work with encoded data regularly, these tools complement what you can do here:
- JSON Formatter -- format, minify, validate, and transform JSON data
- URL Encode Decode -- encode and decode URL components
- HTML Formatter -- format and beautify HTML documents
- UUID Generator -- generate unique identifiers in multiple formats
- Hash Generator -- generate MD5, SHA-1, SHA-256, and other hash values
- JavaScript Preview -- run JavaScript live with DOM inspection and console capture