2026-05-18 · 1 min read
HTML entity encoding in APIs and templates
Escape user content before embedding into HTML or JSON string fields.
HTMLsecurityXSS
Key takeaways
- Encoding is context-specific—HTML entities do not replace URL or JavaScript escaping.
- Decode only trusted content; never decode attacker-controlled strings before rendering.
Pick the right escape
Use HTML entity encoding for text nodes; use URL encoding for query parameters; use JSON string escaping inside JSON.
Chain tools in that order when building composite payloads.
FAQ
Does this prevent XSS?
It helps when inserting text into HTML, but use framework auto-escaping and CSP as primary defenses.
Named vs numeric entities?
Both are supported for common characters; verify output in your target template engine.