220 units · 20 categories. BigNumber decimal precision. SI + US customary + niche (data rates, illuminance, electric). Bidirectional conversion.
Embed unit conversions, timezones, holidays, and name analysis in any website. 220 units · 600 timezones · 200+ countries · Korean romanization (4 systems).
Zero dependencies. Shadow DOM. 4 themes. BigNumber precision. Luxon timezone math. Free CDN.
Four utility-focused sites for daily reference. Each powers one widget package with high-precision domain logic.
220 units · 20 categories. BigNumber decimal precision. SI + US customary + niche (data rates, illuminance, electric). Bidirectional conversion.
600 IANA timezones · 25K+ cities. DST rules, business hours, sunrise/sunset, world clock. Luxon timezone math.
holidayfyi.com · npm
200+ countries. Easter calculation, lunar calendar (Chinese/Korean/Hindu), regional variations, religious + public holidays.
Korean romanization (4 systems: RR/MR/Yale/NK), Five Elements (Wuxing) analysis, CJK stroke counts, given-name etymology.
fyipedia.com · umbrella ecosystem
Utility FYI is one of 11 FYI Families. Cross-references to Creative FYI (color/font for visual tools), Nature FYI (units of mass for biology), and more.
Embed unit converters, timezone clocks, holiday lists, and name analysis in one line of HTML.
<!-- Load any combination of utility widget scripts -->
<script src="https://cdn.jsdelivr.net/npm/unitfyi-embed@1/dist/embed.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/timefyi-embed@1/dist/embed.min.js"></script>
<!-- Drop widgets anywhere -->
<div data-unitfyi="entity" data-slug="meter"></div>
<div data-timefyi="entity" data-slug="asia-seoul"></div>UnitFYI supports 220 units across 20 categories: length, mass, volume, area, temperature, pressure, energy, power, force, speed, time, frequency, data, data-rate, currency, fuel-economy, angle, illuminance, and electric. Decimal precision via BigNumber. Browse categories or use the converter.
TimeFYI covers all 600+ IANA timezone names + 25K+ cities. Each timezone has DST rules, UTC offset, current time, sunrise/sunset (where applicable), and business hours calculation. World clock view shows multiple cities simultaneously.
HolidayFYI covers 200+ countries with public + religious holidays. Includes Easter calculation, lunar holiday lookup (Chinese New Year, Korean Chuseok, Hindu festivals), regional variations (US state-specific, German bundesland). Browse countries.
NameFYI specializes in Korean name romanization (4 systems): Revised Romanization, McCune-Reischauer, Yale, North Korean. Plus Five Elements (Wuxing) name analysis + CJK stroke counts. Try the romanizer or Five Elements analyzer.
Yes. UnitFYI uses BigNumber for arbitrary-precision arithmetic. TimeFYI uses Luxon for timezone math. HolidayFYI uses precomputed lunar tables to 2100. NameFYI Five Elements use deterministic stroke-count algorithm. No floating-point artifacts.