Run results for: JSON.parse vs fast-json-parse

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/135.0.0.0 Safari/537.36

Browser: Chrome 135

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Benchmark engine: Benchmark.js

JSON.parse valid

6.4M/s

fast-json-parse valid

3.3M/s

fast-json-parse invalid

50K/s

JSON.parse invalid

49K/s

JSON.parse combined

49K/s

fast-json-parse combined

48K/s

View exact numbers

Test name	Executions per second
✓ JSON.parse valid	6,356,832 Ops/sec
fast-json-parse valid	3,276,283 Ops/sec
fast-json-parse invalid	49,644 Ops/sec
JSON.parse invalid	48,635 Ops/sec
JSON.parse combined	48,558 Ops/sec
fast-json-parse combined	48,234 Ops/sec

Script Preparation code:

var valid = ['false', 'true', '2.5', '{"test": 1}'];
var invalid = ['025', 'text', 'FALSE', 'TRUE', '{cat}'];
var combined = [...valid, ...invalid];

// src from https://www.npmjs.com/package/fast-json-parse
function Parse (data) {
  if (!(this instanceof Parse)) {
    return new Parse(data)
  }
  this.err = null
  this.value = null
  try {
    this.value = JSON.parse(data)
  } catch (err) {
    this.err = err
  }
}

var fastJsonParse = Parse;

Tests:

JSON.parse combined
combined.map((value) => { try { return JSON.parse(value); } catch(e) { return null; } })
JSON.parse invalid
invalid.map((value) => { try { return JSON.parse(value); } catch(e) { return null; } })
JSON.parse valid
valid.map((value) => { try { return JSON.parse(value); } catch(e) { return null; } })
fast-json-parse combined
combined.map((value) => { const result = fastJsonParse(value); return result.err ? null : result.value; })
fast-json-parse invalid
invalid.map((value) => { const result = fastJsonParse(value); return result.err ? null : result.value; })
fast-json-parse valid
valid.map((value) => { const result = fastJsonParse(value); return result.err ? null : result.value; })