Benchmark: Ways to cache Intl.NumberFormat

HTML Preparation code:

<script src='https://cdn.jsdelivr.net/npm/lodash@4.17.21/lodash.min.js'></script>

Script Preparation code:

const formatOptions = {
  minimumFractionDigits: 0,
  maximumFractionDigits: 0,
  useGrouping: false,
  style: 'percent',
};

const staticInstanceDe = new Intl.NumberFormat("de", formatOptions);
const staticInstanceFr = new Intl.NumberFormat("fr", formatOptions);

const lodashCache = _.memoize(
    (locale, options) => new Intl.NumberFormat(locale, options),
    (locale, options) => `${locale}-${JSON.stringify(options)}`,
);

const mapCache = new Map();
const getMapCacheInstance = (locale, options) => {
  let lang;
  if (!mapCache.has(locale)) {
    lang = new Map();
    mapCache.set(locale, lang);
  } else {
    lang = mapCache.get(locale);
  }
  if (!lang.has(options)) {
    const newInstance = new Intl.NumberFormat(locale, options);
    lang.set(options, newInstance);
    return newInstance;
  }
  return lang.get(options);
}

const objCache = {};
const getObjCacheInstance = (locale, options) => {
  let lang = objCache[locale];
  if (!lang) {
    lang = {};
    objCache[locale] = lang;
  }
  if (!lang[options]) {
    const newInstance = new Intl.NumberFormat(locale, options);
    lang[options] = newInstance;
    return newInstance;
  }
  return lang[options];
}

Tests:

Always new instance
new Intl.NumberFormat("de", formatOptions).format(0.123) new Intl.NumberFormat("fr", formatOptions).format(0.123)
static global instance
staticInstanceDe.format(0.123) staticInstanceFr.format(0.123)
Lodash cache
lodashCache("de", formatOptions).format(0.123) lodashCache("fr", formatOptions).format(0.123)
Custom cache with maps
getMapCacheInstance("de", formatOptions).format(0.123) getMapCacheInstance("fr", formatOptions).format(0.123)
Custom cache with objects
getObjCacheInstance("de", formatOptions).format(0.123) getObjCacheInstance("fr", formatOptions).format(0.123)

Historical Performance Data aggregated from 5 community runs

Desktop Results:

Chrome 5 runs

static global instance

2.5M/s

Custom cache with maps

2.5M/s

Custom cache with objects

1.7M/s

Lodash cache

1.1M/s

Always new instance

69K/s

Fastest: static global instance (36.7x faster)

View exact numbers

✓ static global instance: 2,528,241 ops/sec
• Custom cache with maps: 2,455,811 ops/sec
• Custom cache with objects: 1,727,712 ops/sec
• Lodash cache: 1,149,347 ops/sec
• Always new instance: 68,960 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Always new instance
static global instance
Lodash cache
Custom cache with maps
Custom cache with objects

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 9 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.0.1 Safari/605.1.15

Browser/OS: Safari 26 on Mac OS X 10.15.7

View result in a separate tab

Custom cache with maps

1.7M/s

static global instance

1.6M/s

Custom cache with objects

1.5M/s

Lodash cache

1.0M/s

Always new instance

28K/s

View exact numbers

Test name	Executions per second
✓ Custom cache with maps	1,681,500 Ops/sec
static global instance	1,584,848 Ops/sec
Custom cache with objects	1,484,761 Ops/sec
Lodash cache	1,044,699 Ops/sec
Always new instance	28,432 Ops/sec

Ways to cache Intl.NumberFormat (version: 2)

Try to test different ways of keeping Intl.NumberFormat instances for better performance.

Comparing performance of: `Always new instance vs static global instance vs Lodash cache vs Custom cache with maps vs Custom cache with objects`

Created: one year ago by: Registered User

Go to the latest result

Always new instance

static global instance

Lodash cache

Custom cache with maps

Custom cache with objects

Historical Performance Data aggregated from 5 community runs

Desktop Results:

Chrome 5 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Ways to cache Intl.NumberFormat (version: 2)

Try to test different ways of keeping Intl.NumberFormat instances for better performance.

Comparing performance of: Always new instance vs static global instance vs Lodash cache vs Custom cache with maps vs Custom cache with objects

Created: one year ago by: Registered User

Go to the latest result

Always new instance

static global instance

Lodash cache

Custom cache with maps

Custom cache with objects

Historical Performance Data aggregated from 5 community runs

Desktop Results:

Chrome 5 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Related benchmarks

Comparing performance of: `Always new instance vs static global instance vs Lodash cache vs Custom cache with maps vs Custom cache with objects`