Named HTML entities encoder and decoder

Use it free in the browser for template hygiene and content cleanup, or call the API at $0.002 per successful request when pipelines need reproducible named-entity transforms in CI and backend services.

What named HTML entities are and what this tool returns

The JSON response always includes result for the transformed string, mode echoing encode or decode, encoding fixed to html_entities_named, input_length plus output_length so tests can assert sizes, and either entities_encoded or entities_decoded so you can confirm how many characters or names were rewritten. There is no partial silent skip for unknown names: either every named entity is defined in the map or the request fails with invalid_input.

How text and mode are read and how results stay reproducible

Encode walks the string by Unicode code point and replaces every character that has a preferred name in the reverse table with &name;, leaving letters, digits, and other unmapped Unicode unchanged so readable copy stays readable. When several historical names could map to the same character, encode prefers a stable canonical choice: amp, lt, gt, quot, and apos for the five specials, and the first declared name for other symbols. Decode scans for well-formed named entities that end with a semicolon: a name of a leading letter followed by letters or digits. The preferred payload field is text, with aliases input, value, s, and html so forms, query strings, and SDK clients can reuse the same contract without renaming columns. Mode defaults to encode and accepts decode explicitly; aliases op, direction, and action map to the same switch for scripts that already use those names. Bare ampersands that do not form a complete named entity are left untouched so incomplete drafts do not explode, but a complete unknown name such as &notanentity; raises invalid_input with a message that names the bad reference. Pair the free browser run on this page with the priced API when you need the identical mathematical result inside an automated pipeline without re-implementing entity tables yourself. Invalid inputs return invalid_input and are not charged, which keeps validation cheap while successful transforms remain a fixed item price at $0.002.

Where named HTML entity encode and decode fit in markup workflows

Backend services encode dynamic titles and labels before embedding them in HTML snippets or JSON that later becomes HTML, preferring mnemonic names that humans can audit in source control. On this page the work runs entirely in your browser; through the API each successful lookup costs $0.002, failed validation is not charged, and nothing is stored after the response returns. That split—free interactive exploration and a priced, identical API—matches the rest of the KIT tier-A catalog and lets you move from a classroom demo to an automated pipeline without changing the encoded result. Pair it with HTML sanitize or minify helpers when you need broader markup cleanup, and with other encoding endpoints when you are building a small lab of free, deterministic text tools focused on named references people actually search for.