JOrtho - a Java spell-checking library


JOrtho (Java Orthography) is a spell-checker entirely written in Java. Its dictionaries are based on the free Wiktionary project and can therefore be updated by virtually any language.

The library works with any JTextComponent from the Swing frame work. This includes JTextPane, JEditorPane and JTextArea. It is an Open Source project hosted on SourceForge.


What does the library do when it is bound to a JTextCompontent?

  • highlight the potentially wrongly spelled word
  • offer a context menu with suggestions for a correct form of the word
  • context menu with option to change the checking language
  • dialog (when pressing F7 key) for continuous spell check of the text
  • user defined dictionary for words that are not in the global one (this is an option that appears inside the continuous checking dialog)
  • translated spell checker GUI so users will see buttons and labels in the language of the current locale
  • standalone API, no server is required but applets are possible
  • detect capitalization errors
  • enable or disable every feature separately

System Requirements

JOrtho has the following requirements to run smoothly:

  • Java 5 or higher
  • 1-2MB free memory in the JavaVM (depending on the dictionary)

Who uses JOrtho

This is a list of products that are known to use JOrtho. If you think there are other products, please let us know that we can complete this list.


The tool and the dictionaries can be downloaded at SourceForge.

The API is available here.


JOrtho is published under the GNU General Public License (GPL) for inclusion in programs published under a compatible open-source license. If you want to use JOrtho in a commercial product then you can order it in our shop.

i-net software offers a JOrtho Commercial license with it's own license agreement.

If you have further questions on licensing, please contact our support teams.

Please read the license agreement before you purchase the JOrtho Commercial License.


  • Which languages are supported by JOrtho? Please have a look at the download area at SourceForge.
  • JOrtho does not support my language. How can I add a language? Have a look at the Wiktionary project for your language. There should be at minimum 50.000 entries. Translate the resource file of JOrtho into your language and send it to us. Help us on parsing the Wiktionary for your language. We will have some questions to the language dependent format of the flexion (i.e. the various grammatical forms of words).
  • Where can I get support for this tool? For the GPL license, support is available on SourceForge. For the commercial license, support is available via e-mail. For any other questions, please contact us.
  • Some important words are missing in the dictionary. How can I add them? Look in the Wiktionary for your language. If the word is missing, then add it. If the word exists, then look at how recent the entry was added/created. We will be creating new dictionaries periodically. It is possible that JOrtho parses the entry incorrectly. In this case, please let us know.

Creating Dictionaries

File Format

The dictionaries files are a list of words. Every word is saved in a separate line. The word list is saved in UTF8 encoding. The resulting file is compressed with gzip.

Generate dictionaries from Wiktionary

The dictionaries are based on the Wiktionary dictionaries. This is a step by step description how you can generate a new dictionary version.

  1. Download the data from Wiktionary. The file for the English language is Replace the red part with your language. Some languages also require the data of the English Wiktionary (currently Polish and Arabic)
  2. Extract the XML file from the archive
  3. Download or check out the sources of JOrtho and compile it.
  4. Execute the command
    java -Xmx256M com.inet.jorthodictionaries.BookGenerator en <wiktionary folder>
    Replace the red part with your language.

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