Papa Parse

The powerful, in-browser CSV parser for big boys and girls

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// Parse CSV string
var data = Papa.parse(csv);

// Convert back to CSV
var csv = Papa.unparse(data);

// Parse local CSV file
Papa.parse(file, {
	complete: function(results) {
		console.log("Finished:", results.data);
	}
});

// Stream big file in worker thread
Papa.parse(bigFile, {
	worker: true,
	step: function(results) {
		console.log("Row:", results.data);
	}
});
Version
4.4

Features

Now the fastest JavaScript CSV parser for the browser

The world's first multi-threaded CSV parser for the browser

Papa can handle files gigabytes in size without crashing

Use Papa when performance, privacy, and correctness matter to you

Papa alleviates privacy concerns related to uploading files

Malformed CSV is handled gracefully with a detailed error report

  • Stream local and remote files
  • Multi-threaded
  • Header row support
  • Type conversion
  • Skip commented lines
  • Fast mode
  • Graceful error handling
  • Optional sprinkle of jQuery


  • People Papa

    SmartyStreets verifies addresses, many of which are in CSV files. Papa Parse can process huge files in the browser. "We rapidly built an awesome client-side file processor with Papa Parse."

    MetaReader helps you see your data from a meta level before you start detailed analysis. "Papa Parse made it very easy to load and ready user CSV files in the browser on the client side."

    EpiML is an agent-based mathematical model for the web, still in its early stages of development. "Papa makes it so easy to use CSV, which is good for scientists."

    CSV Parsing

    "Isn't parsing CSV just String.split(',')?"

    Heavens, no. Papa does it right. Just pass in the CSV string with an optional configuration.

    var results = Papa.parse(csvString, config);
    /*
    	results = {
    		data: [ ... ],    // parsed data
    		errors: [ ... ],  // errors encountered
    		meta: {	... }     // extra parse info
    	}
    */

    Delimiter Detection

    "But I don't know the delimiter..."

    That's okay. Papa will scan the first few rows to find the right delimiter.

    var results = Papa.parse(csvString);
    console.log(results.meta.delimiter);
    // "\t"

    Local Files

    "Great, but I have a file to parse."

    Then give Papa a File instead of a string. Since file parsing is asynchronous, don't forget a callback.

    Papa.parse(fileInput.files[0], {
    	complete: function(results) {
    		console.log(results);
    	}
    });

    Remote Files

    "No—I mean, the file isn't on my computer."

    Oh, well then just pass in the URL and—of course—a callback.

    Papa.parse("http://example.com/file.csv", {
    	download: true,
    	complete: function(results) {
    		console.log(results);
    	}
    });

    Streaming

    "Did I mention the file is huge?"

    That's what streaming is for. Specify a step callback to receive the results row-by-row. This way, you won't load the whole file into memory and crash the browser.

    Papa.parse("http://example.com/big.csv", {
    	download: true,
    	step: function(row) {
    		console.log("Row:", row.data);
    	},
    	complete: function() {
    		console.log("All done!");
    	}
    });

    Multi-Threading

    "Lovely. Now my web page locked up."

    That happens when a long-running script is executing in the same thread as the page. Use a Worker thread by specifying worker: true. It may take slightly longer, but your page will stay reactive.

    Papa.parse(bigFile, {
    	worker: true,
    	step: function(row) {
    		console.log("Row:", row.data);
    	},
    	complete: function() {
    		console.log("All done!");
    	}
    });

    Type Conversion

    "Hey, these numbers are parsed as strings."

    Everything is parsed as strings. If you want numbers and booleans, you can enable dynamic typing to do the conversion for you.

    // Converts numeric/boolean data
    var results = Papa.parse(csv, {
    	dynamicTyping: true
    });

    Comments

    "I forgot to mention: my CSV files have comments in them."

    Okay, first off: that's really weird. But fortunately, you can skip those lines... just specify the comment string.

    // Mostly found in academia, some CSV files
    // may have commented lines in them
    var results = Papa.parse(csv, {
    	comments: "#"
    });

    Error Handling

    "Aw, shoot. Errors."

    Papa handles errors pretty well. The CSV standard is somewhat loose ambiguous, so Papa is designed for edge cases. For example, mismatched fields won't break parsing.

    // Example error:
    {
    	type: "FieldMismatch",
    	code: "TooManyFields",
    	message: "Expected 3 fields, but parsed 4",
    	row: 1
    }

    jQuery Plugin

    "Can I use Papa with jQuery?"

    Sure, but it's not required. You can use jQuery to select file input elements and then parse their files. Papa exposes its file parsing API as a jQuery plugin only when jQuery is defined. Papa Parse has no dependencies.

    $("input[type=file]").parse({
    	config: {
    		complete: function(results, file) {
    			console.log("This file done:", file, results);
    		}
    	},
    	complete: function() {
    		console.log("All files done!");
    	}
    });

    JSON to CSV

    "Last thing: what about converting JSON to CSV?"

    Call unparse() instead of parse(), passing in your array of arrays or array of objects. Papa will figure it out.

    // Output is a properly-formatted CSV string.
    // See the docs for more configurability.
    var csv = Papa.unparse(yourData);

    Who's Your Papa?

    Lil' Papa (minified) for production use

    Fat Papa (un-minified) for development

    npm
    $ npm install papaparse

    bower
    $ bower install papaparse