csv-parsers-comparison

This project aims to compare all CSV parsers for Java in existence, or at least the ones that seem to work and are available to the general public. There are too many and the intention here is to help you decide which one is the best for you. Commercial parsers are welcome in the test. Please send us the details of your commercial parser and we will include the results.

Currently, we are only testing parsing performance. As the input file, we will be using the famous worldcitiespop.txt, which is made available for free by Maxmind. It contains more than 3 million rows, which should be sufficient for our test.

Building and Running

Prerequisites: Git, wget, gunzip, GNU Patch, Apache Maven 3, and Java 1.6+. The appropriate CSV parser library version will be chosen depending on your JDK version (i.e. 1.6, 1.7, or 1.8).

If you wish to reproduce our performance results:

$ git clone https://github.com/uniVocity/csv-parsers-comparison.git
$ cd csv-parsers-comparison
$ wget http://www.maxmind.com/download/worldcities/worldcitiespop.txt.gz
$ gunzip worldcitiespop.txt.gz
$ git checkout src/
$ mvn clean package
$ java -jar target/csv-parsers-comparison-1.0-uber.jar .

NOTE: the . at the end of the last command, this tells Java the folder containing the worldcitiespop.txt. You can alternatively specify a path to any folder that contains a worldcitiespop.txt file.

If you just want to run from the main() method, download the worldcitiespop.txt and place it under src/main/resources/ before executing the main class PerformanceComparison.java.

Our test is very simple and involves just counting the number of rows read from the input file. The implementation using each parser is here.

Important

The input file is not RFC 4180 compliant. We generate a compliant version using the HugeFileGenerator class to test the parsers against a generated file with the same data, but enclosed within quotes and properly escaped.

It's important to notice that there's no such thing as a CSV standard and we do not recommend you to use parsers that follow the RFC strictly, as they will blow up in face of non-compliant inputs. The reality is: your parser must be ready to process crooked data instead of going belly up. In the end, your client is the one who tells you what you must swallow, and in many circumstances it's not up to you to decide how your data is going to be generated.

We generate a RFC compliant version to give those sensitive parsers a chance to see how they perform. Once again, we consider their usage risky.

CSV Parsers

This is the list of all parsers currently tested.

Parser	Version	Website
uniVocity-parsers' CsvParser	2.6.0	www.univocity.com
CSVeed	0.5.0	csveed.org
Apache Commons CSV	1.4/1.5	[commons.apache.org/proper/commons-csv] (http://commons.apache.org/proper/commons-csv)
OpenCSV	4.1	opencsv.sourceforge.net
SuperCSV	2.4.0	supercsv.sourceforge.net
JavaCSV	2.0	sourceforge.net/projects/javacsv
jCSV	1.4.0	code.google.com/p/jcsv
flatpack	3.4.2/4.0.1	flatpack.sourceforge.net
SimpleCSV	2.1	github.com/quux00/simplecsv
gj-csv	1.0	?
esperio-csv	5.5.0/7.0.0	www.espertech.com
way-io	1.25.0/2.1.0	www.objectos.com.br
beanIO	2.1.0	beanio.org
jackson-dataformat-csv	2.6.7/2.7.9/2.9.4	github.com/FasterXML/jackson-dataformat-csv
OsterMiller Utils	1.07.00	ostermiller.org/utils/CSV.html
SimpleFlatMapper CSV parser	3.15.9	github.com/arnaudroger/SimpleFlatMapper
Diergo Easy CSV Streamable	3.1.0	github.com/aburmeis/decs
Product Collections	1.4.5	github.com/marklister/product-collections

Statistics (updated 28th of February, 2018)

Results will vary depending on your setup and hardware, here is mine:

• CPU: AMD Ryzen 7 1700 Eight-Core Processor @ 4.0 GHz
• RAM: 32 GB
• Storage: 1TB SSD drive
• OS: Arch Linux 64-bit
• JDK: 9.0.4 64-bit (Linux)
• JDK: 1.8.0_144 64-bit (Linux)
• JDK: 1.7.0_80 64-bit (Linux)
• JDK: 1.6.0_45 64-bit (Linux)

Note uniVocity-parsers provides an option to select the fields you are interested in, and our parsers will execute faster by not processing values that are not selected. It makes quite a difference in performance but we removed this test as the other parsers don't have a similar feature.

Processing 3,173,958 rows of non RFC 4180 compliant input. No quoted values.

JDK 9

Parser	Average time	% Slower than best	Best time	Worst time
uniVocity CSV parser	739 ms	Best time!	707 ms	768 ms
SimpleFlatMapper CSV parser	861 ms	16%	848 ms	901 ms
Jackson CSV parser	1212 ms	64%	1169 ms	1238 ms
Product Collections parser	1409 ms	90%	1389 ms	1451 ms
Java CSV Parser	1498 ms	102%	1490 ms	1508 ms
JCSV Parser	1681 ms	127%	1660 ms	1710 ms
Oster Miller CSV parser	1772 ms	139%	1762 ms	1780 ms
Gen-Java CSV	1799 ms	143%	1790 ms	1805 ms
Simple CSV parser	1861 ms	151%	1832 ms	1900 ms
SuperCSV	1893 ms	156%	1858 ms	1964 ms
OpenCSV	2022 ms	173%	2007 ms	2037 ms
Apache Commons CSV	2424 ms	228%	2409 ms	2442 ms
Way IO Parser	2577 ms	248%	2532 ms	2638 ms

JDK 8

Parser	Average time	% Slower than best	Best time	Worst time
uniVocity CSV parser	723 ms	Best time!	716 ms	736 ms
SimpleFlatMapper CSV parser	769 ms	6%	761 ms	778 ms
Jackson CSV parser	924 ms	27%	914 ms	944 ms
Diergo Easy CSV Streamable	1186 ms	64%	1173 ms	1217 ms
Simple CSV parser	1273 ms	76%	1255 ms	1297 ms
Product Collections parser	1328 ms	83%	1314 ms	1354 ms
JCSV Parser	1440 ms	99%	1432 ms	1459 ms
SuperCSV	1497 ms	107%	1478 ms	1511 ms
Java CSV Parser	1512 ms	109%	1495 ms	1548 ms
Gen-Java CSV	1517 ms	109%	1440 ms	1541 ms
Oster Miller CSV parser	1639 ms	126%	1634 ms	1649 ms
OpenCSV	1687 ms	133%	1676 ms	1702 ms
Apache Commons CSV	2197 ms	203%	2187 ms	2208 ms
Way IO Parser	2318 ms	220%	2260 ms	2368 ms

JDK 7

Parser	Average time	% Slower than best	Best time	Worst time
uniVocity CSV parser	771 ms	Best time!	742 ms	827 ms
SimpleFlatMapper CSV parser	888 ms	15%	881 ms	899 ms
Jackson CSV parser	1015 ms	31%	986 ms	1055 ms
JCSV Parser	1371 ms	77%	1362 ms	1376 ms
Product Collections parser	1405 ms	82%	1376 ms	1482 ms
Simple CSV parser	1450 ms	88%	1362 ms	1594 ms
Java CSV Parser	1477 ms	91%	1464 ms	1518 ms
SuperCSV	1500 ms	94%	1477 ms	1520 ms
OpenCSV	1529 ms	98%	1518 ms	1545 ms
Oster Miller CSV parser	1615 ms	109%	1594 ms	1638 ms
Gen-Java CSV	2096 ms	171%	2059 ms	2195 ms
Way IO Parser	2118 ms	174%	2102 ms	2139 ms
Apache Commons CSV	2204 ms	185%	2194 ms	2226 ms

JDK 6

Parser	Average time	% Slower than best	Best time	Worst time
uniVocity CSV parser	824 ms	Best time!	811 ms	844 ms
SimpleFlatMapper CSV parser	879 ms	6%	871 ms	887 ms
Jackson CSV parser	1071 ms	29%	1062 ms	1085 ms
Product Collections parser	1368 ms	66%	1360 ms	1375 ms
SuperCSV	1561 ms	89%	1537 ms	1629 ms
OpenCSV	1579 ms	91%	1555 ms	1604 ms
Java CSV Parser	1605 ms	94%	1596 ms	1617 ms
Oster Miller CSV parser	1744 ms	111%	1736 ms	1757 ms
JCSV Parser	1766 ms	114%	1758 ms	1776 ms
Simple CSV parser	1905 ms	131%	1888 ms	1918 ms
Apache Commons CSV	2105 ms	155%	2094 ms	2123 ms
Gen-Java CSV	2135 ms	159%	2085 ms	2200 ms
Way IO Parser	2148 ms	160%	2133 ms	2161 ms

• Esperio-csv and CSVeed were unable to process the file and threw exceptions.
• Flatpack hanged so I had to remove it from the test here.
• BeanIO threw an exception I could understand and debug. Turns out it is unable to parse fields when the quote character is part of the value, e.g. value1, val"ue2, value3 .

Processing 3,173,958 rows of RFC 4180 compliant input. All values quoted.

Note this input file has all the values enclosed within quotes. We generated the input like this on purpose as the algorithm to process quotes is a bit different.

JDK 9

Parser	Average time	% Slower than best	Best time	Worst time
uniVocity CSV parser	982 ms	Best time!	966 ms	1002 ms
SimpleFlatMapper CSV parser	1137 ms	15%	1125 ms	1156 ms
Jackson CSV parser	1338 ms	36%	1313 ms	1369 ms
Product Collections parser	1480 ms	50%	1467 ms	1504 ms
Java CSV Parser	1735 ms	76%	1718 ms	1761 ms
JCSV Parser	2043 ms	108%	2029 ms	2055 ms
Gen-Java CSV	2162 ms	120%	2134 ms	2182 ms
Oster Miller CSV parser	2353 ms	139%	2335 ms	2389 ms
SuperCSV	2511 ms	155%	2495 ms	2522 ms
Simple CSV parser	2544 ms	159%	2529 ms	2558 ms
OpenCSV	2665 ms	171%	2647 ms	2686 ms
Apache Commons CSV	2917 ms	197%	2851 ms	3020 ms
Way IO Parser	3243 ms	230%	3227 ms	3252 ms
Esperio CSV parser	3406 ms	246%	3349 ms	3458 ms
Bean IO Parser	3740 ms	280%	3681 ms	3792 ms

JDK 8

Parser	Average time	% Slower than best	Best time	Worst time
uniVocity CSV parser	855 ms	Best time!	839 ms	870 ms
SimpleFlatMapper CSV parser	964 ms	12%	959 ms	971 ms
Jackson CSV parser	1023 ms	19%	1009 ms	1058 ms
Diergo Easy CSV Streamable	1385 ms	61%	1378 ms	1394 ms
Product Collections parser	1388 ms	62%	1386 ms	1391 ms
Java CSV Parser	1642 ms	92%	1635 ms	1650 ms
JCSV Parser	1756 ms	105%	1739 ms	1765 ms
Simple CSV parser	1813 ms	112%	1804 ms	1841 ms
Gen-Java CSV	1954 ms	128%	1950 ms	1961 ms
SuperCSV	1989 ms	132%	1975 ms	2001 ms
Apache Commons CSV	2152 ms	151%	2145 ms	2161 ms
OpenCSV	2234 ms	161%	2227 ms	2256 ms
Oster Miller CSV parser	2292 ms	168%	2285 ms	2306 ms
Way IO Parser	2915 ms	240%	2905 ms	2932 ms
Esperio CSV parser	2981 ms	248%	2944 ms	3044 ms
Bean IO Parser	3238 ms	278%	3219 ms	3263 ms

JDK 7

Parser	Average time	% Slower than best	Best time	Worst time
uniVocity CSV parser	960 ms	Best time!	945 ms	984 ms
SimpleFlatMapper CSV parser	1021 ms	6%	1018 ms	1031 ms
Jackson CSV parser	1102 ms	14%	1092 ms	1112 ms
Product Collections parser	1475 ms	53%	1467 ms	1492 ms
Java CSV Parser	1659 ms	72%	1652 ms	1665 ms
JCSV Parser	1709 ms	78%	1689 ms	1728 ms
SuperCSV	1848 ms	92%	1837 ms	1858 ms
Simple CSV parser	1939 ms	101%	1887 ms	2028 ms
OpenCSV	2022 ms	110%	2013 ms	2032 ms
Oster Miller CSV parser	2422 ms	152%	2406 ms	2436 ms
Gen-Java CSV	2551 ms	165%	2546 ms	2562 ms
Way IO Parser	2621 ms	173%	2613 ms	2628 ms
Apache Commons CSV	2804 ms	192%	2798 ms	2814 ms
Bean IO Parser	3460 ms	260%	3420 ms	3564 ms
Esperio CSV parser	4021 ms	318%	3996 ms	4058 ms

JDK 6

Parser	Average time	% Slower than best	Best time	Worst time
SimpleFlatMapper CSV parser	1187 ms	Best time!	1183 ms	1193 ms
uniVocity CSV parser	1216 ms	2%	1206 ms	1226 ms
Jackson CSV parser	1397 ms	17%	1391 ms	1413 ms
Product Collections parser	1488 ms	25%	1478 ms	1496 ms
SuperCSV	1873 ms	57%	1864 ms	1892 ms
OpenCSV	2205 ms	85%	2198 ms	2214 ms
JCSV Parser	2227 ms	87%	2210 ms	2250 ms
Oster Miller CSV parser	2323 ms	95%	2316 ms	2334 ms
Java CSV Parser	2437 ms	105%	2428 ms	2454 ms
Simple CSV parser	2510 ms	111%	2472 ms	2609 ms
Gen-Java CSV	2590 ms	118%	2542 ms	2609 ms
Apache Commons CSV	2739 ms	130%	2734 ms	2748 ms
Way IO Parser	2831 ms	138%	2819 ms	2843 ms
Bean IO Parser	3685 ms	210%	3661 ms	3721 ms
Esperio CSV parser	4002 ms	237%	3986 ms	4039 ms

• CSVeed was unable to process the file and threw exception with the message "Parsing symbol OTHER_SYMBOL [44] in state ESCAPING".
• Flatpack blew up the Java heap space so I had to remove it from the test here.

Reliability (updated 9th of October, 2017)

The following parsers were unable to process the RFC 4180 compliant file correctness.csv. This test is executed using the class CorrectnessComparison.java

Parser	Error
CSVeed	CSVeed threw exception "Illegal state transition: Parsing symbol QUOTE_SYMBOL [34] in state INSIDE_FIELD"
jCSV Parser	JCSV Parser produced ["Year,Make,Model,Description,Price"] instead of ["Year", "Make", "Model", "Description", "Price"]
Simple CSV parser	Simple CSV parser threw exception "The separator, quote, and escape characters must be different!"
Way IO Parser	Way IO Parser threw exception "Could not convert to class java.lang.String"
Gen-Java CSV	Gen-Java CSV produced 7 rows instead of 6
Flatpack	Flatpack produced 5 rows instead of 6

The exact same errors have been reported 3 years ago when I last updated this page. Just avoid these parsers.

Conclusion

Currently, three parsers stand out as the fastest CSV parsers for Java:

uniVocity-parsers, SimpleFlatMapper and Jackson CSV. Keep in mind that Simpleflatmapper is a very simple implementation that does not provide any customization options. Results are affected by a simple change in the JDK version, however these three parsers are always at the top.

We will keep working to improve the performance of our parsers, and will try to update the results of this benchmark every time a new parser is added to the list.

Head on to the uniVocity-parsers github page to get access to its source code and documentation. Contributions are welcome.

Commercial support is available for your peace of mind. Click here to learn more.