Base64 Encoder and Decoder

Base64 Encoder & Decoder: Core Features and Principles

When you need to embed binary data, such as images or keys, into text-based protocols (like HTTP or JSON) or transmit them safely as URL parameters, using raw bytes directly can cause garbled text or transmission errors. This tool is designed to solve this exact problem. Using the Base64 algorithm, it converts any binary data (or byte sequences converted from specific character encodings) into a string composed of 64 ASCII characters (A-Z, a-z, 0-9, +, /, =), enabling safe text-based data representation. Simply input your original text or Base64 string, and the tool will perform a two-way conversion, outputting the corresponding Base64 encoded result or the decoded original text.

Why Choose Our Base64 Encoder & Decoder?

• Supports Standard and URL-Safe Modes: Offers standard Base64 encoding (including +, /, =) and URL-safe Base64 encoding (replaces + with -, / with _, and removes the = padding), meeting the needs of various transmission scenarios.
• Compatible with Multiple Character Encodings: Core processing is byte-based, allowing you to specify character sets like UTF-8 or Latin1 for the text before encoding or after decoding. This ensures accurate processing of multilingual text and prevents garbled output.
• Real-Time Two-Way Automatic Conversion: Automatically detects your intended operation upon input and displays results in real time. Seamlessly switch between encoding and decoding modes for an intuitive and efficient experience.

How to Use

1. Enter the original text you want to encode in the "Before Encoding" text box, or enter the Base64 string you want to decode in the "After Encoding" text box.
2. Depending on your needs, select "Standard Base64" or "URL-Safe Base64" from the "Standard" dropdown menu.
3. Select the character set corresponding to your original text (e.g., UTF-8) from the "Character Encoding" dropdown menu.
4. View the conversion results displayed in real time in the corresponding output box.

Frequently Asked Questions (FAQ)

Q: What should I do if the decoded Base64 text is garbled?
This is usually caused by using different character sets for encoding and decoding. Please ensure that you have selected the same character set (e.g., UTF-8) in the "Character Encoding" dropdown menu that was used when the original text was encoded. Base64 encodes bytes, and the character set determines the rules for converting text to bytes.

Q: What is URL-safe Base64?
URL-safe Base64 is a variant that replaces the "+" and "/" characters in standard Base64 results with "-" and "_" respectively, and typically omits the "=" padding character. This allows the encoded string to be used directly as a URL parameter or filename without requiring additional URL encoding.

Important Notes

Please note that Base64 encoding increases the data size by approximately 33%. When decoding, ensure that the input Base64 string is formatted correctly (the length is usually a multiple of 4, and the character set is valid). This tool performs all calculations locally in your browser; your input data is never uploaded to our servers. However, we still recommend exercising caution when handling highly sensitive information. For extremely long text, please be aware of browser performance limitations.

Technical Notes & Tips

Base64 is not an encryption algorithm; it is merely an encoding format. Its contents can be easily decoded, so please do not use it to secure sensitive information. In actual development, it is commonly used to embed small images in Data URLs (e.g., ), or to pass structured information in HTTP Basic Auth and the Payload section of JSON Web Tokens (JWT). A typical example: encoding the text "Hello" using UTF-8 and standard Base64 results in "SGVsbG8="; encoding the same text using the URL-safe mode results in "SGVsbG8".