How to Encode and Decode Base64 Online
Base64 is an encoding scheme that converts binary data into ASCII text, making it safe to transmit over text-based protocols like email, JSON, or URLs. It's commonly used for embedding images in HTML, encoding authentication tokens, and transferring files. This guide shows you how to encode and decode Base64 using fixie.tools — a free online tool that works with text and files, no signup required.
Step 1: Open the Base64 Encoder/Decoder
Navigate to fixie.tools/base64 in your web browser. The tool works entirely in your browser for privacy — no data is uploaded to servers. No account or signup is required. The tool works on all devices including mobile.
Step 2: Choose Encode or Decode
Select whether you want to encode data to Base64 or decode Base64 back to its original form. Encoding converts text or files into Base64 strings. Decoding converts Base64 strings back into readable text or downloadable files. The tool shows different interfaces optimized for each operation.
Step 3: Enter Your Data
For encoding, paste text into the input field or click to upload a file (images, documents, etc.). For decoding, paste the Base64 string you want to decode. The tool supports files up to 25MB and automatically detects whether the input is valid Base64. Syntax highlighting helps identify malformed Base64 strings.
Step 4: Process the Data
Click the encode or decode button to process your data. Encoding and decoding are instant for most data sizes. The tool displays the result in the output area. For decoded files, you'll see the file type and size with a download button. For encoded data, you can copy the Base64 string to your clipboard.
Step 5: Copy or Download the Result
For encoded text, use the copy button to grab the Base64 string for use in your code, APIs, or HTML. For decoded files, click the download button to save the original file to your device. The tool includes additional options like URL-safe encoding (replaces + and / characters) and line wrapping for specific use cases.