I Built a Browser-Only HTML Entity Encoder/Decoder — Named, Decimal & Hex, 246 Tests

📰 Dev.to · Dev Nestio

Learn to build a browser-only HTML entity encoder/decoder to escape special characters in user input

intermediate Published 27 Jun 2026

Action Steps

Build an HTML entity encoder using JavaScript to replace special characters with their corresponding entities
Run the encoder with sample user input to test its functionality
Configure the encoder to handle named, decimal, and hex entities
Test the encoder with 246 test cases to ensure its accuracy
Apply the encoder to your web application to sanitize user input

Who Needs to Know This

Frontend developers and web developers can benefit from this tool to ensure user input is properly sanitized and secure

Key Insight

💡 Properly escaping special characters in user input is crucial for web application security

Key Takeaways

Learn to build a browser-only HTML entity encoder/decoder to escape special characters in user input

Every developer has hit this: you need to escape <, >, &, and quotes before dropping user...