String Converter

An encoding converter is an essential tool for developers that converts data between various formats. It supports Base64, URL, HTML encoding, JSON/YAML/XML/CSV conversion, and string case transformation. Extremely useful in web development, API communication, and data processing, it automates manual conversion tasks to save time and prevent errors. It is indispensable for REST API development, frontend development, backend data processing, and data migration tasks.

Base64 is a method to convert binary data to ASCII text. It is used when transmitting images and files in text format, commonly seen in email attachments, data URLs, and API responses. In web development, small images are embedded directly into HTML/CSS using data:image/png;base64, format to reduce HTTP requests. Also used in JWT authentication and HTTP Basic authentication, but size increases by 33%, making it unsuitable for large data.

URL encoding (percent encoding) is a method to safely include special characters in URLs. Spaces become %20, and non-ASCII characters like Korean are converted to UTF-8 bytes in percent format. Essential for URL query strings, path parameters, and form data transmission, particularly important in search engine queries, API calls, and RESTful routing. Incorrect encoding can cause 404 errors or data loss, and reserved characters (&, =, ?, #) must be properly encoded.

HTML escaping is an important security technique to prevent XSS attacks. Special characters like <, >, &, ", ' are converted to HTML entities to prevent them from being interpreted as code. User input displayed on web pages must be escaped, for example, making <script> tags display as text only. All user input, database output, and API responses must be processed when displayed in HTML, and using it together with Content Security Policy (CSP) further strengthens security.

Conversion between JSON, YAML, XML, CSV is essential in modern development. JSON is most widely used in web APIs with fast parsing, YAML is human-readable and used in configuration files (Docker Compose, Kubernetes). XML is used in legacy systems and SOAP services, CSV is utilized in Excel and database work. Understanding the pros and cons of each format and converting appropriately is important, useful for configuration file management, CI/CD pipelines, and data migration tasks.

In practice, use the auto-copy feature to shorten workflows, and save to browser bookmarks for quick access. Do not input security-sensitive data (passwords, API keys) into online tools; use local scripts and always validate encoding results. Use UTF-8 encoding as default to prevent internationalization issues, and understand the purpose and limitations of each encoding method. Used daily in JWT token debugging, image data URL conversion, API gateway implementation, and data migration.