This web application allows you to check that a sequence of characters has been entered in the correct order in a document or web page, and optionally to attempt automatically to fix any errors. It will pick up most common problems, such as typing เ+เ instead of แ, or typing vowels and tone marks in the wrong order, for example typing ก+◌้+◌ุ+ง, rather than ก+◌ุ+◌้+ง. Whilst these typing problems don't affect readability, they affect the searchability of the document, and the ability of search engines correctly to index the document.

How to Use

  1. Paste the text to be checked into the text area. This text can be:
    • Plain text
    • Formatted text (e.g. with bold, italics, etc.)
    • Copied web page content
    • HTML
  2. Click on the "Check" button. The text will then be sequence checked, and incorrect sequences highlighted in bold and red. The number of errors found is shown below the text area. If it's zero then the text is fine, and there's no need to attempt to fix it. (This step is optional if you simply want to fix the text.)
  3. To attempt to fix the text, click the "Fix" button. The number of remaining errors (if any) will be shown below the text area. If it's not zero, you may wish to click the "Check" button again to show where those errors are. You can now copy and paste the fixed text, should you wish to do so.
  4. The "Clear" button clears the text area and resets the application.


  1. The application does not guarantee that the fixed text will make sense - only that the character sequence will be valid.
  2. This application will only work in browsers which support rich text editing.
  3. It is not guaranteed that all the formatting will be preserved. The extent of preservation is dependent upon the specific browser's capabilities.
  4. The sequence checking is based upon the TIS 1566 (1999) standard.

Corrections Applied

The following table shows some of the problems identified and the fixes applied.

เ+เCharacters replaced
◌ํ+า◌ำCharacters replaced
ก+◌้+◌ุ+งก+◌ุ+◌้+งVowel and tone mark switched
น+ะ+◌่น+◌่+ะVowel and tone mark switched
ก+า+◌ีก+าExtra characters deleted*

* Which extra character is deleted varies according to context - it may be the first or second.