Data & Formatting · In-Browser Regular Expression Lab

CSV Parser Regex — Match Values with Quotes and Commas

Splits a CSV line into fields respecting quotes around fields with embedded commas.

Pattern:

Regular Expression Pattern & Flags

Flags:

//g

Live Test String

Match Found

Load Sample:

Match Inspection & Details3 matches

Match #1:"John Doe"

Match #2:,28

Match #3:,"Engineer, Lead"

Test Samples Verification Matrix

Expected Valid Samples (Should Match)

"John Doe",28,"Engineer, Lead" Pass

1,2,3 Pass

apple,"green, sour",true Pass

Expected Invalid Samples (Must Reject)

broken"quote Accepted (Fail)

Code Implementation Generator

// JavaScript / TypeScript (ES6+)
const pattern = /(?:^|,)(?:"([^"]*(?:""[^"]*)*)"|([^,"]*))/g;
const text = "\"John Doe\",28,\"Engineer, Lead\"";

const isMatch = pattern.test(text);
console.log("Is Match:", isMatch);

if (isMatch) {
  const matches = text.match(pattern);
  console.log("Matches:", matches);
}

Regular Expression Token Breakdown

Parses CSV fields supporting RFC 4180 escaped double quotes (`""`). Each component of the regular expression serves a distinct syntactical purpose as mapped below:

Token Pattern	Name / Component	Function & Rule
(?:^\|,)	Start or comma	Matches line start or delimiter.
"([^"]*...)"	Quoted value	Captures text enclosed in double quotes.
([^,"]*)	Unquoted value	Captures normal text without quotes or commas.