Free online tool for Base64 encoding/decoding and URL encoding/decoding. Convert strings to Base64 or URL-safe characters. Essential tool for developers.
1. Select Type: Choose Base64 or URL encoding/decoding.
2. Enter Text: Type the text you want to convert.
3. Click Button: Click encode or decode button to convert.
4. Copy Result: Use copy button to copy result to clipboard.
Base64 is a method to encode binary data as text. It's used for email attachments, image data URLs, API authentication tokens, etc. It uses only 64 safe ASCII characters (A-Z, a-z, 0-9, +, /) to represent all data.
URL encoding converts unsafe characters in URLs to % followed by hexadecimal codes. It's needed when including spaces, non-ASCII characters, or special characters in URLs. Example: space becomes %20, and non-ASCII characters become UTF-8 codes starting with %.
Encoding is the process of converting data into a different format according to specific rules. It is used to safely transmit or store text, images, and binary data on computers. Unlike encryption, encoding is not for security purposes but for compatibility and transmission reliability — anyone can decode it.
Base64 converts binary data to text and is used for sending email attachments, embedding images directly in HTML/CSS as Data URLs, and generating HTTP basic authentication headers. It is especially useful when binary data needs to be included in text-based formats like JSON or XML. A downside is that Base64 encoding increases data size by about 33%.
URLs can only contain letters, numbers, and certain special characters, so Korean characters, spaces, and special characters cannot be included directly. URL encoding converts these characters to % followed by hexadecimal codes so they can be safely included in URLs. For example, if a search query contains Korean characters, the browser automatically URL-encodes them before sending to the server.
Character encoding (UTF-8, EUC-KR, etc.) is the method of converting characters into bytes that a computer can store. Base64 and URL encoding are a higher layer that converts data already expressed as bytes back into a text-safe format. In modern web development, characters are first encoded in UTF-8, and then Base64 or URL encoding is applied additionally as needed.
Base64 uses 64 safe ASCII characters to represent all binary data. URL encoding (percent encoding) follows RFC 3986 and converts characters not allowed in URLs into %XX format. HTML encoding converts special HTML characters like &, <, and > into entities to prevent XSS attacks.
When passing special characters as query parameters in REST API development, URL encoding must be applied. To send an image in a JSON body for a file upload API, convert it to Base64. OAuth and JWT tokens also use Base64 encoding to transform binary data into URL-safe strings.
Base64 is not encryption, so encoding sensitive data in Base64 does not guarantee security. When outputting user input in HTML, apply HTML encoding to prevent XSS attacks. When including user input in SQL queries, use parameterized queries rather than encoding — that is the correct security approach.