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/97.0.4692.99 Safari/537.36

Browser: Chrome 97

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
JSON.parse combined	40965.1 Ops/sec
JSON.parse invalid	39802.7 Ops/sec
JSON.parse valid	1019044.0 Ops/sec
fast-json-parse combined	32928.7 Ops/sec
fast-json-parse invalid	36088.7 Ops/sec
fast-json-parse valid	433727.1 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; })

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

JSON.parse combined

JSON.parse invalid

JSON.parse valid

fast-json-parse combined

fast-json-parse invalid

fast-json-parse valid