Paste either snippet into your page — a Custom HTML block on WordPress, Shopify, or Squarespace works too. Both snippets update live as you customize, so what you copy is exactly what you configured.
<!-- Free Crypto Converter widget by haynes lab — https://hayneslab.dev/tools/widgets/crypto-converter -->
<script data-hl-config='{"BTC":{"USD":67000,"EUR":62000},"ETH":{"USD":3500,"EUR":3250},"SOL":{"USD":160,"EUR":148}}' data-hl-default-from="BTC" data-hl-default-to="USD" data-hl-amount="0.5">
/*!
* haynes lab — Crypto Converter widget (free)
* Docs & embed code: https://hayneslab.dev/tools/widgets/crypto-converter
*/
(function () {
'use strict';
var PREFIX = 'hlw-crypto-converter';
var STYLE_ID = 'hlw-crypto-converter-styles';
function findScript() {
return document.currentScript ||
document.querySelector('script[src*="widgets/crypto-converter.js"]');
}
function injectStyles() {
if (document.getElementById(STYLE_ID)) return;
var css =
'.' + PREFIX + ', .' + PREFIX + ' * { box-sizing: border-box; }' +
'.' + PREFIX + ' { position: relative; max-width: 420px; margin: 0 auto; padding: 24px 24px 32px;' +
' font-family: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;' +
' font-size: 16px; line-height: 1.5; color: #1f2937; background: #ffffff;' +
' border: 1px solid #e5e7eb; border-radius: 12px; }' +
'.' + PREFIX + '__title { margin: 0 0 16px; font-size: 18px; font-weight: 600; color: #111827; }' +
'.' + PREFIX + '__label { display: block; font-size: 12px; font-weight: 600; text-transform: uppercase;' +
' letter-spacing: 0.04em; color: #6b7280; margin: 0 0 6px; }' +
'.' + PREFIX + '__field { margin-bottom: 14px; }' +
'.' + PREFIX + '__input, .' + PREFIX + '__select { width: 100%; padding: 10px 12px; font: inherit;' +
' color: #1f2937; background: #ffffff; border: 1px solid #d1d5db; border-radius: 8px; }' +
'.' + PREFIX + '__input:focus, .' + PREFIX + '__select:focus { outline: 2px solid var(--hlw-accent);' +
' outline-offset: 0; border-color: var(--hlw-accent); }' +
'.' + PREFIX + '__pair { display: flex; gap: 10px; }' +
'.' + PREFIX + '__pair .' + PREFIX + '__field { flex: 1; min-width: 0; margin-bottom: 0; }' +
'.' + PREFIX + '__result { margin-top: 18px; padding: 14px 16px; background: #f9fafb;' +
' border: 1px solid #e5e7eb; border-radius: 8px; }' +
'.' + PREFIX + '__result-value { font-size: 22px; font-weight: 700; color: var(--hlw-accent);' +
' word-break: break-all; }' +
'.' + PREFIX + '__result-rate { font-size: 13px; color: #6b7280; margin-top: 2px; }' +
'.' + PREFIX + '__note { margin: 12px 0 0; font-size: 11px; color: #9ca3af; }' +
'.' + PREFIX + '__credit { position: absolute; right: 10px; bottom: 6px; font-size: 11px;' +
' display: inline-flex; align-items: center; gap: 4px; color: #9ca3af; text-decoration: none; }' +
'.' + PREFIX + '__credit svg { display: block; }' +
'.' + PREFIX + '__credit:hover { color: #6b7280; text-decoration: underline; }' +
'@media (max-width: 420px) { .' + PREFIX + '__pair { flex-direction: column; } }';
var style = document.createElement('style');
style.id = STYLE_ID;
style.textContent = css;
document.head.appendChild(style);
}
function el(tag, className, text) {
var node = document.createElement(tag);
if (className) node.className = className;
if (text != null) node.textContent = text;
return node;
}
function logoSvg() {
var svgNS = 'http://www.w3.org/2000/svg';
var svg = document.createElementNS(svgNS, 'svg');
svg.setAttribute('viewBox', '0 0 32 32');
svg.setAttribute('width', '13');
svg.setAttribute('height', '13');
svg.setAttribute('aria-hidden', 'true');
svg.setAttribute('focusable', 'false');
function circle(cx, cy, r, attrs) {
var c = document.createElementNS(svgNS, 'circle');
c.setAttribute('cx', cx);
c.setAttribute('cy', cy);
c.setAttribute('r', r);
for (var key in attrs) c.setAttribute(key, attrs[key]);
svg.appendChild(c);
}
circle(16, 16, 16, { fill: '#0f0a0a' });
circle(16, 16, 12, { fill: 'none', stroke: '#fff5f5', 'stroke-width': 1, opacity: 0.3 });
circle(16, 16, 9, { fill: 'none', stroke: '#fff5f5', 'stroke-width': 1, opacity: 0.5 });
circle(16, 16, 6, { fill: 'none', stroke: '#fff5f5', 'stroke-width': 1.2, opacity: 0.9 });
circle(16, 16, 3, { fill: '#06b6d4' });
circle(24.5, 7.5, 2, { fill: '#f97316' });
circle(7, 16, 1.8, { fill: '#f97316' });
circle(20, 20, 1.5, { fill: '#f97316' });
return svg;
}
function validRates(data) {
if (!data || typeof data !== 'object' || Array.isArray(data)) return null;
var clean = {};
Object.keys(data).forEach(function (crypto) {
var row = data[crypto];
if (!row || typeof row !== 'object' || Array.isArray(row)) return;
var out = {};
Object.keys(row).forEach(function (fiat) {
var n = Number(row[fiat]);
if (isFinite(n) && n > 0) out[fiat] = n;
});
if (Object.keys(out).length) clean[crypto] = out;
});
return Object.keys(clean).length ? clean : null;
}
function loadRates(script, done) {
var raw = script.getAttribute('data-hl-config');
if (raw) {
try {
var rates = validRates(JSON.parse(raw));
if (rates) return done(rates);
console.warn('[haynes lab crypto-converter] data-hl-config has no usable rates ({CRYPTO:{FIAT:number}}).');
} catch (e) {
console.warn('[haynes lab crypto-converter] data-hl-config is not valid JSON.', e);
}
}
var endpoint = script.getAttribute('data-hl-endpoint');
if (!endpoint) {
if (!raw) console.warn('[haynes lab crypto-converter] Provide data-hl-config (rates JSON) or data-hl-endpoint. Nothing rendered.');
return done(null);
}
fetch(endpoint)
.then(function (res) {
if (!res.ok) throw new Error('HTTP ' + res.status);
return res.json();
})
.then(function (data) {
var rates = validRates(data);
if (!rates) console.warn('[haynes lab crypto-converter] Endpoint returned no usable rates ({CRYPTO:{FIAT:number}}).');
done(rates);
})
.catch(function (e) {
console.warn('[haynes lab crypto-converter] Failed to load rates from data-hl-endpoint.', e);
done(null);
});
}
function formatMoney(n, fiat) {
var decimals = n >= 1 ? 2 : 6;
try {
return new Intl.NumberFormat(undefined, {
style: 'currency', currency: fiat,
minimumFractionDigits: 2, maximumFractionDigits: decimals
}).format(n);
} catch (e) {
return n.toLocaleString(undefined, { maximumFractionDigits: decimals }) + ' ' + fiat;
}
}
function build(script, rates) {
var cryptos = Object.keys(rates);
var fiats = [];
cryptos.forEach(function (c) {
Object.keys(rates[c]).forEach(function (f) {
if (fiats.indexOf(f) === -1) fiats.push(f);
});
});
var title = script.getAttribute('data-hl-title') || 'Crypto Converter';
var accent = script.getAttribute('data-hl-accent') || '#f97316';
var defaultFrom = (script.getAttribute('data-hl-default-from') || '').toUpperCase();
var defaultTo = (script.getAttribute('data-hl-default-to') || '').toUpperCase();
var amount0 = parseFloat(script.getAttribute('data-hl-amount'));
if (!isFinite(amount0) || amount0 < 0) amount0 = 1;
if (cryptos.indexOf(defaultFrom) === -1) defaultFrom = cryptos[0];
if (fiats.indexOf(defaultTo) === -1) defaultTo = fiats[0];
injectStyles();
var root = el('div', PREFIX);
root.style.setProperty('--hlw-accent', accent);
root.appendChild(el('h3', PREFIX + '__title', title));
var amountField = el('div', PREFIX + '__field');
var amountLabel = el('label', PREFIX + '__label', 'Amount');
var amount = el('input', PREFIX + '__input');
amount.type = 'number';
amount.min = '0';
amount.step = 'any';
amount.value = String(amount0);
amount.id = PREFIX + '-amount-' + Math.random().toString(36).slice(2, 8);
amountLabel.setAttribute('for', amount.id);
amountField.appendChild(amountLabel);
amountField.appendChild(amount);
root.appendChild(amountField);
function makeSelect(id, labelText, options, selected) {
var field = el('div', PREFIX + '__field');
var label = el('label', PREFIX + '__label', labelText);
var select = el('select', PREFIX + '__select');
select.id = id;
label.setAttribute('for', id);
options.forEach(function (code) {
var opt = el('option', null, code);
opt.value = code;
if (code === selected) opt.selected = true;
select.appendChild(opt);
});
field.appendChild(label);
field.appendChild(select);
return { field: field, select: select };
}
var uid = amount.id.replace(PREFIX + '-amount-', '');
var from = makeSelect(PREFIX + '-from-' + uid, 'From', cryptos, defaultFrom);
var to = makeSelect(PREFIX + '-to-' + uid, 'To', fiats, defaultTo);
var pair = el('div', PREFIX + '__pair');
pair.appendChild(from.field);
pair.appendChild(to.field);
root.appendChild(pair);
var result = el('div', PREFIX + '__result');
result.setAttribute('aria-live', 'polite');
var valueEl = el('div', PREFIX + '__result-value');
var rateEl = el('div', PREFIX + '__result-rate');
result.appendChild(valueEl);
result.appendChild(rateEl);
root.appendChild(result);
function update() {
var n = parseFloat(amount.value);
var crypto = from.select.value;
var fiat = to.select.value;
var rate = rates[crypto] && rates[crypto][fiat];
if (!rate) {
valueEl.textContent = '—';
rateEl.textContent = 'No ' + crypto + '/' + fiat + ' rate in the supplied data.';
return;
}
if (!isFinite(n) || n < 0) n = 0;
valueEl.textContent = formatMoney(n * rate, fiat);
rateEl.textContent = '1 ' + crypto + ' = ' + formatMoney(rate, fiat);
}
amount.addEventListener('input', update);
from.select.addEventListener('change', update);
to.select.addEventListener('change', update);
update();
root.appendChild(el('p', PREFIX + '__note',
'Rates are a snapshot supplied by this site\u2019s owner and may differ from live market prices.'));
var credit = el('a', PREFIX + '__credit');
credit.appendChild(logoSvg());
credit.appendChild(document.createTextNode('Powered by haynes lab'));
credit.href = 'https://hayneslab.dev/tools/widgets/crypto-converter';
credit.target = '_blank';
credit.rel = 'noopener';
root.appendChild(credit);
if (script.parentNode && script.parentNode.nodeName !== 'HEAD') {
script.insertAdjacentElement('afterend', root);
} else {
document.body.appendChild(root);
}
}
function init() {
var script = findScript();
if (!script) {
console.warn('[haynes lab crypto-converter] Could not locate its own script tag. Nothing rendered.');
return;
}
loadRates(script, function (rates) {
if (rates) build(script, rates);
});
}
if (document.body) {
init();
} else {
document.addEventListener('DOMContentLoaded', init);
}
})();
</script>