HTML Entity Encoder & Decoder
HTML Entity Encoder & Decoder: Replaces special HTML characters (<, >, &, ", ') with standard HTML named character entities.
About this html entity encoder & decoder
HTML Entity Encoder & Decoder — browser-based utility.
How this tool works
Implements client-side HTML Entity Encoder & Decoder operations. Replaces special HTML characters (<, >, &, ", ') with standard HTML named character entities specifically designed for a web security auditor encodes dangerous html markup strings to prevent cross-site scripting (xss).
- Input Classification & Format Detection: Automatically distinguishes between second, millisecond, microsecond, and nanosecond timestamp scales, or detects hex/string representation.
- Sanitization & Range Enforcement: Verifies that timestamps fall within valid calendar epochs (-62167219200 to 253402300799) and that UUID strings conform to RFC 4122 hexadecimal grouping.
- Algorithmic Synthesis & Permutation: Generates monotonic timestamp-prefixed binary words or maps characters to standard W3C entity codepoint tables.
- Output Delivery & Verification: Displays human-readable UTC/local dates, hexadecimal representations, and verified entropy statistics.
Worked example
Scenario: Encode the five supported HTML entity characters.
Sample input:
Processing: Apply the fixed encode replacement table.
Illustrative output:
Limits and verification
Rejects timestamps resulting in dates before the year 0001 or after the year 9999. UUID parsing strictly requires 32 hexadecimal digits separated by standard 8-4-4-4-12 hyphens. Non-ASCII characters in HTML entity decoders are checked against the WHATWG Named Character Reference standard.
Examples demonstrate an expected workflow; they do not prove every input or every branch of an external specification. Check important results with an independent source before using them for money, security, compliance, safety, or irreversible file changes.
Browser processing boundary
Tool input is processed by code running in the browser and is not intentionally sent to a CZOA processing API. The page can still request ordinary site assets, analytics, or advertising when those services are enabled. Browser extensions and managed-device software remain outside this tool's control.
Relevant references
These references govern or help explain the format, protocol, or calculation used here. Listing a reference does not claim certification or complete implementation of every optional feature.
Content owner: CZOA Tools · Last reviewed: 2026-09-15 · Review methodology
How to use it
- Enter, paste, or select your input data into the HTML Entity Encoder & Decoder workspace controls.
- Review available parameter fields, units, formats, or options configured for your task.
- Click the action button or observe immediate live calculations rendered in your browser runtime.
- Inspect the resulting output and any diagnostic messages, then copy or download the result if needed.
Frequently asked questions
Which characters does HTML Entity Converter encode?+
In encode mode it replaces only `&`, `<`, `>`, double quote, and apostrophe with the fixed named entities. For `<a&"`, the browser result is `<a&"`; it does not encode every Unicode character.
How does decode mode operate?+
Decode mode assigns the entered text to a browser textarea’s `innerHTML` and reads its `value`, so browser entity parsing determines the result. The non-DOM fallback recognizes only five named forms.
What is outside this converter’s HTML coverage?+
It is text replacement, not HTML sanitization or DOM parsing. It does not validate tags, preserve markup structure, protect against unsafe insertion, or give a security decision.
Does this converter send entered entity text to a service?+
No. Encode and decode run in the current page through string replacement or a textarea DOM value. It has no file picker, upload control, or tool request; ordinary page resources do not process the entered text.