Enable GZIP compression in tomcat

What is GZIP?

It is a compression format created by Jean-Loup Gailly and Mark Adler. Version 0.1 was first publicly released on October 31, 1992.

GZIP is based on the DEFLATE algorithm, which is a combination of LZ77 and Huffman coding. DEFLATE was intended as a replacement for LZW and other patent-encumbered data compression algorithms which, at the time, limited the usability of compress and other popular archivers.

How does it helps in improving performance of my web page?

Modern browser like Internet Explorer, Firefox, Opera etc supports gzip compressed content. These browsers are capable of uncompressing gzip data into plain text. Servers like Apache, Tomcat, JBoss etc supports gzip compression too. Hence if gzip is enabled in such servers, the response if first compressed and then send to client. Hence this increase performance by many folds.

How to enable GZIP in my tomcat server?

Here is how to enable GZIP compression on Tomcat: edit file /conf/server.xml and add to the HTTP Connector configuration something like this:

noCompressionUserAgents="gozilla, traviata" 

An example of a HTTP Connector configuration with compression enabled could be:


Check out following header information before enabling GZIP.

And after enabling GZIP look at the size of the webpage and the time taken for loading:

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  • Aditya 28 November, 2008, 17:55

    He dude, why do you wanna do compression on tomcat/coyote..
    most of the people ,when they go production, put the tomcat behind an apache or lighttpd or nginix , as a cluster
    why not the actual webserver do the compression..tomcat compresses in java….while these web servers do it natively..thus much faster and production suitable.

    from somewhere on internet:
    this could certainly be useful if you are running Tomcat standalone, and using apache compression is simply unavailable.

    anyways gud job.

  • Viral Patel 1 December, 2008, 10:15

    Thanks Aditiya for the comment…
    Definitely Apache server can be used that can do this.. But sometime back, I wanted to use only Tomcat and hence this code.

    anyways. thanks for the info :)

  • Sateesh 27 February, 2009, 17:02

    Can anyone help me?????

    I have modified the server.xml conf file to set the \"compression\" properties as specified above in the connector tag.

    I have tested this in FireFox in which I am able to notice the difference in the size. But When tested in the IE7 there is no difference in the size of the page. Can anyone explain me how to figure out the issue with IE7.

  • Viral Patel 27 February, 2009, 18:19

    Hi Sateesh,
    Use some plugins for IE to check HTTP Header and see if the CONTENT-ENCODING is GZIP. You can use http://www.debugbar.com/download.php to check this.

  • Sateesh 2 March, 2009, 11:25

    Thanks Viral for your help.

    I had installed the debugger and checked for the output and not found the Content-Encoding, but seen Transfer-Encoding for which the value is \"chunked\". In IE I noticed the size is 6030 bytes but in FF it is 1519 bytes.

    I turned off the Compression and verified the output. The size is same in IE and FF (6030 bytes). Now the Transfer-Encoding header was vanished. Can you kindly let me know why the gzip is not working in IE and how to initialize the compression in IE.

    Thanks in advance.

  • Ali Virani 10 April, 2009, 0:28

    I turned on tomcat compression, but I require a java client to get the result that is returned and decompress the data in the client. I have tried to use GZipInputStream, but I get IOException: GZip trailer. Can any one help? Ignoring this block is not an option.

  • Lovelesh Singh 11 May, 2009, 18:54

    Hi Dear,
    I have enabled this option but after that web page is opening without compress mode, please help…?

  • Ashish Tonse 15 June, 2009, 21:07

    @Lovelesh – Make sure you also add the mime types for javascript and css. My tomcat wasn’t compressing those until I added these mimetypes:


  • Lovelesh Singh 30 June, 2009, 16:16

    Hi Ashish, thanks for reply.
    I have added as given your reply but it is still working with unzip mode: I am adding here code please review:

    ..please help

  • Muiz 11 October, 2009, 16:38

    Hi all,
    Now i would like to compress the javascript and css files in tomcat 6.0.20 (windows vista),
    1. Moidified server.xml like this:

    2. then test it in firefox 3.5, but i seem doesn’t work, why?
    Can you help me?

    Thanks in advance!

  • Muiz 11 October, 2009, 16:40

    1. Moidified server.xml like this:
    ..Connector port=”8080″ protocol=”HTTP/1.1″
    noCompressionUserAgents=”gozilla, traviata”

  • Muiz 11 October, 2009, 17:14

    Thanks guys,

    This function is working fine!
    It’s my problem: I should clear firefox recent history first and then test it.

    Best regards!

  • Rasha 15 October, 2009, 14:12

    Hi all,
    Really a nice and useful article.

    But I am also facing the IE problem that the response is not compressed. I installed the debug bar and checked. No ‘CONTENT-ENCODING : GZIP’ in the response. Also the response size is the same with/without the compression.

    Any idea?

  • choesang 3 November, 2009, 15:13

    Hi Viral,
    i got the same problem like Muiz, the same configuration and Tomcat doesn’t do gzip. any Ideas??

  • Viral Patel 3 November, 2009, 21:20

    @rasha, @choesang: Generally the problem that you are facing is due to browser cache issue. Clear your browser cache and try again.

  • Deckard Cain 5 November, 2009, 21:39

    Simply, IE is not a browser..

  • Dave 7 November, 2009, 4:35

    Where can I find info on how a client can UNCOMPRESS this data? All these articles/topics assume the server is hit from a browser. The browser handles uncompressing the data automatically. I’m not hitting my server from a browser. I’m using another client program.

  • Intesar 21 November, 2009, 12:07

    Worked like a charm!

    ..Connector port=”8080″ protocol=”HTTP/1.1″
    noCompressionUserAgents=”gozilla, traviata”

  • Prakash Suthar 3 December, 2009, 14:13


    Thanks in advance.

    I am using WAS5.1 and J2EE 1.4.
    I want to use GZip compression in my Struts application.
    I am able to use this compression for .jsp and .html file.
    Once I configure GZip compression for (/*) patten, it gives below exception.

    I am able to used GZip compression for struts application in Tomcat environment, but it does not work for Struts action in WAS5.1.

    [12/3/09 14:32:00:216 IST] 5a8b8c0a WebGroup E SRVE0026E: [Servlet Error]-[]: java.lang.ClassCastException
    at com.ibm.ws.cache.servlet.CacheProxyResponse.isCommitted(CacheProxyResponse.java(Compiled Code))
    at com.ibm.ws.webcontainer.webapp.WebAppRequestDispatcher.forward(WebAppRequestDispatcher.java(Compiled Code))
    at org.apache.struts.action.RequestProcessor.doForward(RequestProcessor.java:1069)
    at org.apache.struts.action.RequestProcessor.processForwardConfig(RequestProcessor.java:455)
    at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:279)

    Let me know if you need some more details.

  • Agus 14 July, 2010, 14:05

    Hi Viral,

    I have turned On the compression on my tomcat server. Below is the setting of my server.xml

    And it works on all js files, except ext-all.js file which is around ~650KB, and this file is my main intention of of turning ON the compression. Is there any upper limit on the size of the file to be compressed?

    • Viral Patel 14 July, 2010, 14:09

      @Agus: There is no upper limit on size for compression. Check the mime type that you have specified in server.xml. Is it application/x-javascript? Also try to refresh and clear cache to see if the browser is not serving the js from cache.

  • Agus 23 July, 2010, 6:57

    Hi Viral,

    That’s strange my ext-all.js is not compressed at all.

    Above is the connector settings I have on server.xml. Thank you very much for you help.

  • Agus 23 July, 2010, 6:58

    port=”8180″ maxHttpHeaderSize=”8192″ address=”″
    maxThreads=”150″ minSpareThreads=”25″ maxSpareThreads=”75″
    enableLookups=”false” redirectPort=”9543″ acceptCount=”150″
    connectionTimeout=”20000″ disableUploadTimeout=”true”
    compression=”on” compressionMinSize=”12000″ noCompressionUserAgents=”gozilla,traviata”

  • Agus 23 July, 2010, 6:58

    May I know how to post the code here?

  • sn 19 February, 2011, 22:41

    Nice tutorial, I like most of your blogs. Here’s another tutorial that explains how to enable gzip compression http://www.servletworld.com/tomcat/enable-tomcat-gzip-compression.html

  • Gig 22 March, 2011, 16:31

    I have the same problem with Agus.
    some of my .js files are gzipped, but some are not.

  • John 16 April, 2011, 3:23

    Maybe it will be better to wrap your JS declaration into compressing tag like that

    <script type=”text/javascript” src=”common.js”/>
    <script type=”text/javascript” src=”closure/goog/base.js”/>

    using Granule tag library from http://code.google.com/p/granule/

  • Gustavo 16 September, 2011, 1:11

    Is there any way to set these configurations in WEB-INF/web.xml?

  • Raul 4 January, 2012, 1:15


  • Vicky 1 March, 2012, 17:22

    Thanks for your help my website responding like a speed of light…thanks a ton..

  • Vicky 1 March, 2012, 17:39

    If i use text/javascript then its not working i want to use compressed content of css,js.

  • Sree 16 August, 2012, 20:52

    Does Tomcat support is supported for IE7? If there are any special settings that we need to make in IE7, please share. Thanks

  • giri 22 October, 2012, 17:56

    I have enable gzip compression in server.xml inside tomcat using the following code

    When i check the Firebug-> Under Net->All ..the response header is showing the encoding type as gzip but when i Analyse my we page in yahoo YSlow or Google PageSpeed its listing all the js files and css files are not compressed using gzip

    Please provide some suggestion.

  • NSINGH 27 October, 2012, 2:29

    How do I verify size after I enable compression, I cannot identify the difference with human eye.

  • NSINGH 27 October, 2012, 2:34

    I want to know how much difference in size and time it took end to end. Is there any software I can use. I am using chrome debugger; it does not show any difference under network tab.

  • Rohan 21 May, 2013, 10:19

    Thank you very much Viral.

  • lakshman 28 May, 2013, 18:11

    I have enable gzip compression in server.xml inside tomcat 6.0 using the following code

    When i check the Firebug-> Under Net->All ..the response header is showing the only html pages as encoding type as gzip but i used YSlow and firebug in that all the js files and css files are not compressed .it not showing the gzip in response header for all js and css files…

    could you Please provide some suggestions.I need to do the gzip for js and css files also…

  • Rian 18 September, 2013, 1:46

    Hi viral, thanks for share how to enable Gzip compression in Tomcat server, But i need tutorials for blogger platform, can you help me?


  • Abhishek shukla 27 September, 2013, 18:01

    Hi viral,
    Thanks for this nice post, i really like all post related to java, and i always found all the post help me. Thanks a lot. and keep posting. Thanks.

  • sai 8 October, 2013, 18:01

    hi viral,
    content-encoding is gzip but why the transfer-encoding is chunked after gzip compression.

  • Jonathan Neufeld 25 March, 2014, 2:21

    Great article, this helped me troubleshoot a compression issue, it looks like Apache’s HttpClient library doesn’t handle compression natively.

    You should also note that “force” is a good troubleshooting option for the compression value in lieu of “on”

  • Mrinal 27 April, 2014, 22:01

    I have added the lines and still it doesn’t work. I get “Transfer-encoding:gzip” but no “Content-encoding”. Please guide me at the earliest. Thanks in advance.

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